270695711-vmware-faq.docx

VMware FAQ 1. What is Cloud Computing? Cloud computing is a style of computing that enables on-demand network access to a shared pool of scalable and elastic infrastructure resources. The term cloud computing originates from the standard network diagram where a cloud is used to represent the abstraction of a complex networked system such as the Internet. Cloud computing is a type of computing that relies on sharing computing resources rather than having local servers or personal devices to handle applications. In cloud computing, the word cloud (also phrased as "the cloud") is used as a metaphor for "the Internet," so the phrase cloud computing means "a type of Internet-based computing," where different services -- such as servers, storage and applications -- are delivered to an organization's computers and devices through the Internet. Cloud computing builds on virtualization to create a service-oriented computing model. This is done through the addition of resource abstractions and controls to create dynamic pools of resources that can be consumed through the network. Benefits include economies of scale, elastic resources, self-service provisioning, and cost transparency. 2. What is Virtualization? Virtualization is the creation of a virtual (rather than actual) version of IT resources, such as a hardware platform, operating system (OS), storage device, or network resources. 3. What is the difference between Virtualization and Cloud Computing? Virtualization is the creation of a virtual (rather than actual) version of something, such as a hardware platform, an operating system, a storage device or a network resource. Simply stated, Virtualization is a technique that allows you to run more than one server (or another infrastructure component) on the same hardware. For example, one server is the host server and controls the access to the physical server’s resources. One or more virtual servers then run within containers provided by the host server. The hypervisor software (which controls access to the physical hardware) may run on “bare metal” allowing a user to run multiple operating systems on the same physical hardware, or the hypervisor may run on top of a host operating system, allowing other operating systems to run within this host OS, and so on the same physical hardware. The latter inherently gives lower performance, since it has to go through more layers of software to access the physical resources.

Cloud Computing is the delivery of computing as a service rather than a product, whereby shared resources, software, and information are provided to computers and other devices as a metered service over a network (typically the Internet). Cloud Computing may look like Virtualization because it appears that your application is running on a virtual server detached from any reliance or connection to a single physical host. However, Cloud Computing can be better described as a service where Virtualization is part of a physical infrastructure. Cloud Computing builds on top of a virtualized infrastructure (compute, storage, network) by using standardization and automated delivery to provide service management. This makes monitoring the virtualized resources and the responsible deployment of these resources possible. Virtualization is simply a preparation for the delivery of IT in a very powerful way within an organization. It removes a level of complexity for end users, one that should never have been there in the first place, while primarily cutting costs for the organization. Cloud Computing ties directly to the way an organization uses its IT resources and enables a quantum change in the experience throughout the organization – easing the administrative burden of deploying, managing, delivering IT resources, and providing the ability for end users to request and use virtualized IT resources (or perhaps even an application or a business process where the end user does not have to be aware of the underlying IT resources being used). 4. Why Virtualize? There seems to be a bit of confusion about the benefits of server virtualization, with many tending to focus on cost savings. As a district that has been running a virtual infrastructure for some time, I can honestly say that virtualization is not so much about saving money (although you certainly will) as it is about better resource utilization, more reliability, and greater flexibility. Better resource utilization There is no question that most of our servers are doing nothing about 90% of the time. This becomes quite obvious with even a cursory glance at historical utilization data for any given server. It would seem that the obvious solution for this would be to simply run more applications on each one, but the reality of this is that the more apps you install on one OS, the more unreliable it becomes (especially if it's a Microsoft product.) So, what we all do instead is buy a new machine every time we want a new app that we think is "critical," because we want to be sure it has its own sandbox to play in. So, we find ourselves with racks and racks of servers consuming more and more space (at a cost,) all generating heat which we must cool (at a cost,) all pulling more and more power (at a cost,) all requiring more and more time to manage (at a cost.)

Virtualization offers a way to safely put more than one operating system (or virtual server) on one piece of hardware by isolating each operating system from any others running on the box. Essentially, you are establishing a bunch of sandboxes on one piece of hardware. If one of the virtual servers crashes, hard or soft, it will have no impact on any of the others on the box. Hardware resources are better used since, rather than having 10 independent servers running at 10 percent utilization each, you can have 2 running 5 virtual servers each for a total of 50 percent utilization per box. Better still, if designed properly (more on that later,) should a virtual server require more resources, it can easily and instantly be moved to a machine that offers more, often live and transparently to its end users. More reliability It's important to note, before any discussion on reliability comes into play, that a virtualized operating system is, by nature, relatively hardware agnostic. This means that it (its image, which is) can easily be moved from one piece of hardware to another, even if that hardware is of completely different design, without modification and often without shutting the system down (i.e. live migration.) This can dramatically reduce the time required to bring a failed system back up, as the typical 2-4 hour OS reinstall phase can be eliminated. However, virtualization, by its very design, dramatically increases the impact of a single system failure, as a variety of services will be impacted when multiple virtual servers go down simultaneously. This is where the "designed properly" comes into play. Properly designed, virtualized infrastructure can provide far greater reliability and less down time than an infrastructure of individual machines could ever achieve. The keys to the design are redundancy and shared storage. All individual pieces of server hardware must be redundantly linked to a properly designed SAN or other shared storage device, where all virtual machine images are stored for a user to realize the true reliability benefits of server virtualization. Greater flexibility Finally, and perhaps most importantly, virtualization provides flexibility, or what I like to call, an agile infrastructure. I've already described some of that flexibility in the reliability section - moving virtual machines live from box to box. Imagine, for example that one of your virtual machines is consuming too many resources on the box it's on, let’s say processor time. People are complaining that things are slowing down. You say, "no problem," and move the virtual machine to a box with a free processor. Or, you take advantage of virtual smp, and simply pin another processor to the virtual machine. Ever needed to add more RAM to a server because a process has outgrown its allocation? No problem - simply allocate more RAM to the process. No pulling the server, no extended periods of down time. Deployments are equally easy. Once you have one image of an OS, you know that it will work on any hardware, so you never have to sit and watch an installer run, followed by endless online updates again. Simply copy the image and fire it up - you're ready to install

that new app in less than 5 minutes. How much are you paying people to do this sort of thing, when they could be working on more important things, like innovating! 5. What is Hypervisor? A hypervisor, also called a virtual machine manager, is a program that allows multiple operating systems to share a single hardware host. Each operating system appears to have the host's processor, memory, and other resources all to itself. However, the hypervisor is actually controlling the host processor and a resource, allocating what is needed to each operating system in turn and making sure that the guest operating systems (called virtual machines) cannot disrupt each other. 6. What is VMware HA? VMware vSphere High Availability (HA) provides easy-to-use, cost effective high availability for applications running in virtual machines. In the event of physical server failure, affected virtual machines are automatically restarted on other production servers with spare capacity. In the case of operating system failure, vSphere HA restarts the affected virtual machine on the same physical server. With 2 ESX Servers, a SAN for shared storage, Virtual Center, and a VMHA license, if a single ESX Server fails, the virtual guests on that server will move over to the other server and restart, within seconds. This feature works regardless of the operating system used or if the applications support it. 7. How VMware HA works? VMware HA continuously monitors all virtualized servers in a resource pool and detects physical server and operating system failures. To monitor physical servers, an agent on each server maintains a heartbeat with the other servers in the resource pool such that a loss of heartbeat automatically initiates the restart of all affected virtual machines on other servers in the cluster. VMware HA leverages shared storage and, for FibreChannel and iSCSI SAN storage, the VMware vStorage Virtual Machine File System (VMFS) to enable the other servers in the cluster to safely access the virtual machine for failover. When used with VMware Distributed Resource Scheduler (DRS), VMware HA automates the optimal placement of virtual machines on other servers in the cluster after server failure. To monitor operating system failures, VMware HA monitors heartbeat information provided by the VMware Tools package installed in each virtual machine in the VMware HA cluster. Failures are detected when no heartbeat is received from a given virtual machine within a user-specified time interval. VMware HA ensures that sufficient resources are available in the resource pool at all times to be able to restart virtual machines on different physical servers in the event of server failure.

VMware HA is easily configured for a cluster through VMware vCenter Server. 8. How to get the HA Status? Go to the summary tab of your cluster and click “Cluster Status”. Because vCenter Server 5.0 uses Fault Domain Manager (FDM) agents for High Availability (HA), rather than Automated Availability Manager (AAM) agents, the troubleshooting process has changed. There are other architectural and feature differences that also affect the troubleshooting process:    

One main log file (/var/log/fdm.log) and syslog integration Datastore Heartbeat Reduced Cluster configuration (approximately 1 minute, as opposed to 1 minute per host) FDM does not require that DNS be configured on the hosts, nor does FDM rely on other Layer 3 to 7 network services

9. What is a Slot? A slot is a logical representation of the memory and CPU resources that satisfy the requirements for any powered-on virtual machine in the cluster. In other words a slot size is the worst case CPU and Memory reservation scenario in a cluster. 10. Where is HA configuration and log file in vSphere 4.1? 1. To check the current installed version of HA agent. .. run rpm -qa |grep aam 2. HA agent is installed under /opt/vmware/aam 3. To check HA nodes log..run less /var/log/vmware/aam/aam_config_util_listnodes.log 4. To check HA agent log .. run less /var/log/vmware/aam/agent/run.log 5. To check HA install and current configuration log .... run less /var/log/vmware/aam/aam_config_util_install.log

11. Where is HA configuration and log file in vSphere 5.0? /var/log/fdm.log

12. What is AAM in HA? AAM is the Legato automated availability management. Prior to vSphere 4.1, VMware's HA is actually re-engineered to work with VM's with the help of Legato’s Automated Availability Manager (AAM) software. VMware's vCenter agent (vpxa) interfaces with the VMware HA agent which acts as an intermediary to the AAM software. From vSphere 5.0, it uses an agent called “FDM” (Fault Domain Manager). 13. What is Fault Domain Manager? In and among all its new features, vSphere 5.0 introduces a complete rewrite of vSphere HA clustering. Replacing its earlier technology for vSphere HA (AAM) is a new host agent called the Fault Domain Manager, or FDM. This agent is responsible for monitoring host availability and the power state of protected VMs, with the mission of restarting protected VMs when a host or VM fails. 14. What are prerequisites for VMware HA to work?     

Shared storage for the VMs running in HA cluster Essentials plus, Standard, Advanced, Enterprise and Enterprise Plus Licensing VMHA enabled Cluster At least two shared heartbeat data stores between the hosts in VMware HA cluster Management network redundancy to avoid frequent isolation response in case of temporary network issues (preferred not a requirement)

15. What is the maximum number of hosts supported per HA cluster? Maximum number of hosts in the HA/DRS cluster is 32 16. What is VMware DRS? VMware DRS (Distributed Resource Scheduler) is a utility that balances computing workloads with available resources in a virtualized environment. VMware DRS dynamically balances computing capacity across a collection of hardware resources aggregated into logical resource pools, continuously monitoring utilization across resource pools and intelligently allocating available resources among the virtual machines based on pre-defined rules that reflect business needs and changing priorities. When a virtual machine experiences an increased load, VMware DRS automatically allocates additional resources by redistributing virtual machines among the physical servers in the resource pool. With VMware DRS, users define the rules for allocation of physical resources among virtual machines. The utility can be configured for manual or automatic control. Resource pools can be easily added, removed or reorganized. If desired, resource pools can be isolated between different business units. If the workload on one or more virtual machines drastically changes,

VMware DRS redistributes the virtual machines among the physical servers. If the overall workload decreases, some of the physical servers can be temporarily powered-down and the workload consolidated. Other features of VMware DRS include:        

Dedicated infrastructures for individual business units Centralized control of hardware parameters Continuous monitoring of hardware utilization Optimization of the use of hardware resources as conditions change Prioritization of resources according to application importance Downtime-free server maintenance Optimization of energy efficiency Reduction of cooling costs.

17. What is VMware DPM? VMware Distributed Power Management (DPM) is a pioneering new feature of VMware DRS that continuously monitors resource requirements in a VMware DRS cluster. When resource requirements of the cluster decrease during periods of low usage, VMware DPM consolidates workloads to reduce power consumption by the cluster. When resource requirements of workloads increase during periods of higher usage, VMware DPM brings powered-down hosts back online to ensure service levels are met. VMware DPM allows IT organizations to: • Cut power and cooling costs in the datacenter • Automate management of energy efficiency in the datacenter 18. How Does VMware DRS Work? VMware DRS allocates and balances resources in a DRS cluster. It does this dynamically and continuously monitors for changes in utilization. Resource pools are used to allocate resources to a set of virtual machines in a DRS cluster. When load increases in a VM, DRS will redistribute VMs to other physical servers if required to ensure all VMs get their correct share of resources. When a VM is powered on DRS is used to decide which server it is best to be placed on. If a VM is running and DRS decides that it needs to be placed on another physical server to ensure its requirements are met, vMotion is used. This allows the VM to be moved without powering it off or loss of service, allowing resources to be balanced. 19. What are the requirements for FT?

Here are the requirements for the host. 

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The vLockstep technology used by FT requires the physical processor extensions added to the latest processors from Intel and AMD. In order to run FT, a host must have an FTcapable processor, and both hosts running an FT VM pair must be in the same processor family. CPU clock speeds between the two hosts must be within 400MHz of each other to ensure that the hosts can stay in sync. All hosts must be running the same build of ESX or ESXi and be licensed for FT, which is only included in the Advanced, Enterprise, and Enterprise Plus editions of vSphere. Hosts used together as an FT cluster must share storage for the protected VMs (FC, iSCSI, or NAS). Hosts must be in an HA-enabled cluster. Network and storage redundancy is recommended to improve reliability; use NIC teaming and storage multipathing for maximum reliability. Each host must have a dedicated NIC for FT logging and one for VMotion with speeds of at least 1Gbps. Each NIC must also be on the same network. Host certificate checking must be enabled in vCenter Server (configured in vCenter Server Settings → SSL Settings).

Here are the requirements for the VMs.    

The VMs must be single-processor (no vSMPs). All VM disks must be "thick" (fully allocated) and not "thin." If a VM has a thin disk, it will be converted to thick when FT is enabled. There can be no nonreplayable devices (USB devices, serial/parallel ports, sound cards, a physical CD-ROM, a physical floppy drive, physical RDMs) on the VM. Most guest OSs are supported, with the following exceptions that apply only to hosts with third-generation AMD Opteron processors (i.e., Barcelona, Budapest, Shanghai): Windows XP (32-bit), Windows 2000, and Solaris 10 (32-bit)..

In addition to these requirements, there are also many limitations when using FT, and they are as follows.     

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Snapshots must be removed before FT can be enabled on a VM. In addition, it is not possible to take snapshots of VMs on which FT is enabled. N_Port ID Virtualization (NPIV) is not supported with FT. To use FT with a VM you must disable the NPIV configuration. Paravirtualized adapters are not supported with FT. Physical RDM is not supported with FT. You may only use virtual RDMs. FT is not supported with VMs that have CD-ROM or floppy virtual devices connected to a physical or remote device. To use FT with a VM with this issue, remove the CD-ROM or floppy virtual device or reconfigure the backing with an ISO installed on shared storage. The hot-plug feature is automatically disabled for fault tolerant VMs. To hot-plug devices (when either adding or removing them), you must momentarily turn off FT, perform the hot plug, and then turn FT back on.

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EPT/RVI is automatically disabled for VMs with FT turned on. IPv6 is not supported; you must use IPv4 addresses with FT. VMotion is supported on FT-enabled VMs, but you cannot VMotion both the primary and secondary VMs at the same time. SVMotion is not supported on FT-enabled VMs. In vSphere 4.0, FT was compatible with DRS, but the automation level was disabled for FT-enabled VMs. Starting in vSphere 4.1, you can use FT with DRS when the EVC feature is enabled. DRS will perform initial placement on FT-enabled VMs and also will include them in the cluster's load-balancing calculations. If EVC in the cluster is disabled, the FT-enabled VMs are given a DRS automation level of "disabled". When a primary VM is powered on, its secondary VM is automatically placed, and neither VM is moved for load-balancing purposes.

20. What are prerequisites for VMware DRS to work? Hosts that are added to a DRS cluster must meet certain requirements to use cluster features successfully. Shared Storage Ensure that the managed hosts use shared storage. Shared storage is typically on a SAN, but can also be implemented using NAS shared storage. Shared VMFS Volume Configure all managed hosts to use shared VMFS volumes. Place the disks of all virtual machines on VMFS volumes that are accessible by source and destination hosts. Processor Compatibility To avoid limiting the capabilities of DRS, you should maximize the processor compatibility of source and destination hosts in the cluster. vMotion transfers the running architectural state of a virtual machine between underlying ESX/ESXi hosts. vMotion compatibility means that the processors of the destination host must be able to resume execution using the equivalent instructions where the processors of the source host were suspended. Processor clock speeds and cache sizes might vary, but processors must come from the same vendor class (Intel versus AMD) and the same processor family to be compatible for migration with vMotion. vCenter Server provides features that help ensure that virtual machines migrated with vMotion meet processor compatibility requirements. These features include: 

Enhanced vMotion Compatibility (EVC) – You can use EVC to help ensure vMotion compatibility for the hosts in a cluster. EVC ensures that all hosts in a cluster present the same CPU feature set to virtual machines, even if the actual CPUs on the hosts differ. This prevents migrations with vMotion from failing due to incompatible CPUs.

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CPU compatibility masks – vCenter Server compares the CPU features available to a virtual machine with the CPU features of the destination host to determine whether to allow or disallow migrations with vMotion. By applying CPU compatibility masks to individual virtual machines, you can hide certain CPU features from the virtual machine and potentially prevent migrations with vMotion from failing due to incompatible CPUs.

vMotion Requirements To enable the use of DRS migration recommendations, the hosts in your cluster must be part of a vMotion network. If the hosts are not in the vMotion network, DRS can still make initial placement recommendations. To be configured for vMotion, each host in the cluster must meet the following requirements: 

The virtual machine configuration file for ESX/ESXi hosts must reside on a VMware Virtual Machine File System (VMFS).

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vMotion does not support raw disks or migration of applications clustered using Microsoft Cluster Service (MSCS).

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vMotion requires a private Gigabit Ethernet migration network between all of the vMotion enabled managed hosts. When vMotion is enabled on a managed host, configure a unique network identity object for the managed host and connect it to the private migration network.

21. How vMotion works There are 3 underlying action happening in vMotion. First:The entire state of a virtual machine is encapsulated by a set of files stored on shared storage such as Fibre Channel or iSCSI Storage Area Network (SAN) or Network Attached,Storage (NAS). VMware vStorage VMFS allows multiple ESX to access the same virtual machine files concurrently. Second:The active memory and precise execution state of the virtual machine is rapidly transferred over a high speed network, allowing the virtual machine to instantaneously switch from running on the source ESX host to the destination ESX host. VMotion keeps the transfer period imperceptible to users by keeping track of on-going memory transactions in a bitmap. Once the entire memory and system state has been copied over to the target ESX host,

VMotion suspends the source virtual machine, copies the bitmap to the target ESX host, and resumes the virtual machine on the target ESX host. This entire process takes less than two seconds on a Gigabit Ethernet network. Third:The networks being used by the virtual machine are also virtualized by the underlying ESX host, ensuring that even after the migration, the virtual machine network identity and network connections are preserved. VMotion manages the virtual MAC address as part of the process. Once the destination machine is activated, VMotion pings the network router to ensure that it is aware of the new physical location of the virtual MAC address. Since the migration of a virtual machine with VMotion preserves the precise execution state, the network identity, and the active network connections, the result is zero downtime and no disruption to users. 22. What are vSphere Standard Switches? vSphere standard switches are abstracted network devices. A standard switch can bridge traffic internally between virtual machines in the same port group and link to external networks. You can use standard switches to combine the bandwidth of multiple network adapters and balance communications traffic among them. You can also configure a standard switch to handle physical NIC failover. A vSphere standard switch models a physical Ethernet switch. The default number of logical ports for a standard switch is 120. You can connect one network adapter of a virtual machine to each port. Each uplink adapter associated with a standard switch uses one port. Each logical port on the standard switch is a member of a single port group. Each standard switch can also have one or more port groups assigned to it. When two or more virtual machines are connected to the same standard switch, network traffic between them is routed locally. If an uplink adapter is attached to the standard switch, each virtual machine can access the external network that the adapter is connected to. 23. What is vSphere Distributed Switch? The vSphere Distributed Switch (VDS) simplifies virtual machine networking by enabling you to set up virtual machine access switching for your entire datacenter from a centralized interface. VDS provides: Simplify Virtual Machine Network Configuration

Simplify provisioning, administration and monitoring of virtual networking across multiple hosts and clusters from a centralized interface.   

Central control of virtual switch port configuration, portgroup naming, filter settings, etc Link Aggregation Control Protocol (LACP) - Negotiates and automatically configures link aggregation between vSphere hosts and access layer physical switch Network health check capabilities to verify vSphere to physical network configuration

Enhanced network monitoring and troubleshooting capabilities The vSphere Distributed Switch provides rich monitoring and troubleshooting capabilities to your networking staff      

Support for RSPAN and ERSPAN protocols for remote network analysis IPFIX Netflow version 10 SNMPv3 support Rollback and Recovery for Patching and Updating the Network Configuration Templates to enable backup and restore for virtual networking configuration Network based coredump (Netdump) to debug hosts without local storage

Support advanced vSphere Networking Features The vSphere Distributed Switch provides the building blocks for many advanced networking features in a vSphere environment.     

Core building block for Network I/O Control (NIOC) Maintains network runtime state for virtual machines as they move across multiple hosts, enabling inline monitoring and centralized firewall services Supports third-party virtual switch extensions such as the Cisco Nexus 1000V and IBM 5000v virtual switches Support for SR-IOV (Single Root I/O Virtualization) to enable low latency and high I/O workloads BPDU filter to prevent virtual machines from sending BPDUs to the physical switch

24. What is the difference between standard switch (vSwitch) and distributed switch (dvSwitch)? Both types of switches provide the following:     

Can forward L2 frames Can segment traffic into VLANs Can use and understand 802.1q VLAN encapsulation Can have more than one uplink (NIC Teaming) Can have traffic shaping for the outbound (TX) traffic

These features are available only with Distributed Switch: 

Can shape inbound (RX) traffic

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Has a central unified management interface through vCenter Supports Private VLANs (PVLANs) Provides potential customization of Data and Control Planes

vSphere 5.0 provides these improvements to Distributed Switch functionality:   

Increased visibility of inter-virtual-machine traffic through Netflow Improved monitoring through port mirroring (dvMirror) Support for LLDP (Link Layer Discovery Protocol), a vendor-neutral protocol.

25. What is Port Group? You can think of port groups as templates for creating virtual ports with particular sets of specifications. You can create a maximum of 512 port groups on a single host. Port groups are important particularly for VMotion. To understand why, consider what happens as virtual machines migrate to new hosts using VMotion. Port groups make it possible to specify that a given virtual machine should have a particular type of connectivity on every host on which it might run. Port groups are user-named objects that contain configuration information to provide persistent and consistent network access for virtual Ethernet adapters: • Virtual switch name • VLAN IDs and policies for tagging and filtering • Teaming policy • Layer 2security options • Traffic shaping parameters In short, port group definitions capture all the settings for a switch port. Then, when you want to connect a virtual machine to a particular kind of port, you simply specify the name of a port group with an appropriate definition. Port groups may specify different host-level parameters on different hosts teaming configurations, for example. But the key element is that the result is a consistent view of the network for a virtual machine connected to that port group, whichever host is running it. Note: Port groups do not necessarily correspond one-to-one to VLAN groups. It is possible, and even reasonable, to assign the same VLAN ID to multiple port groups. This would be useful if, for example, you wanted to give different groups of virtual machines different physical Ethernet adapters in a NIC team for active use and for standby use, while all the adapters are on the same VLAN. 26. How many ports we can have on a vSwitch? ESX 2.x allowed only 32 virtual machines per vSwitch. ESX 3.x raised the maximum number of ports to 1016. In ESX 4.x, you can change the number of ports to 24, 56, 120, 248, 504, 1016, 2040, or 4088.

What might seem odd about these numbers is they are exactly eight digits less than what you might expect (32, 64, 128, 256, 512, 1032, 2048, and 4096). So what happened to the other eight ports? Well, those eight ports are there, but they are used by the VMkernel for background monitoring processes. 27. What are the three port groups present in ESX4 server networking ? 1) 2) 3)

Virtual Machine Port Group - Used for Virtual Machine Network Service Console Port Group - Used for Service Console Communications VMKernel Port Group - Used for VMotion, iSCSI, NFS Communications

28. VMware vSphere 5 License types?   

Standard: HA, FT, vMotion, Storage vMotion, vShield Endpoint, Replication Enterprise: Standard + DRS, DPM, Storage APIs, Virtual Serial Port Concentrator Enterprise Plus: Enterprise + Distributed Switch, Storage DRS and Profile-Driven Storage, Host Profiles and Auto Deploy, Storage I/O Control and Network I/O Control

29. How to add license? You can add any number of licenses to the vSphere 5.x inventory. When assigning licenses in 5.x products, you can create a relationship between an asset and a license key. Each asset can be licensed by one and only one license key or it can be unlicensed as an Evaluation Mode. Note: To perform these steps, your vSphere Client needs to be connected to the vCenter Server. Adding License Keys To add licenses: 1. 2. 3. 4. 5. 6. 7.

Log in to the vSphere Client. Click Home. Under the Administration section, click the Licensing icon. Click Manage vSphere Licenses. Enter the License Key in the Enter new vSphere license keys field (one per line). Include labels for new license keys as necessary. Click Add License Keys.

After clicking Add License Keys, you can review the license keys you added, capacity counts, expiration dates, and labels associated with the license keys. 8. Click Next to assign the license keys. Assigning License Keys To assign licenses to the vCenter Server or the ESXi host:

1. 2. 3. 4. 5. 6. 7. 8.

Log in to the vSphere Client. Click Home. Under the Administration section, click the Licensing icon. Choose Evaluation Mode and expand the list. Find the product you want to license. Right-click on the product and click Change License Key. Assign a key from list that was entered previously on Manage License window. Click OK. Verify that the product is licensed now.

30. VMware path selection policies? These pathing policies can be used with VMware ESXi 5.x and ESXi/ESX 4.x: 

Most Recently Used (MRU): Selects the first working path, discovered at system boot time. If this path becomes unavailable, the ESXi/ESX host switches to an alternative path and continues to use the new path while it is available. This is the default policy for Logical Unit Numbers (LUNs) presented from an Active/Passive array. ESXi/ESX does not return to the previous path if, or when, it returns; it remains on the working path until it, for any reason, fails. Note: The preferred flag, while sometimes visible, is not applicable to the MRU pathing policy and can be disregarded.

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Fixed (Fixed): Uses the designated preferred path flag, if it has been configured. Otherwise, it uses the first working path discovered at system boot time. If the ESXi/ESX host cannot use the preferred path or it becomes unavailable, the ESXi/ESX host selects an alternative available path. The host automatically returns to the previously-defined preferred path as soon as it becomes available again. This is the default policy for LUNs presented from an Active/Active storage array.

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Round Robin (RR): Uses an automatic path selection rotating through all available paths, enabling the distribution of load across the configured paths. o o

For Active/Passive storage arrays, only the paths to the active controller will be used in the Round Robin policy. For Active/Active storage arrays, all paths will be used in the Round Robin policy.

Note: This policy is not currently supported for Logical Units that are part of a Microsoft Cluster Service (MSCS) virtual machine. 

Fixed path with Array Preference: The VMW_PSP_FIXED_AP policy was introduced in ESXi/ESX 4.1. It works for both Active/Active and Active/Passive storage arrays that support Asymmetric Logical Unit Access (ALUA). This policy queries the storage array for the preferred path based on the array's preference. If no preferred path is specified by the user, the storage array selects the preferred path based on specific criteria.

Note: The VMW_PSP_FIXED_AP policy has been removed from ESXi 5.0. For ALUA arrays in ESXi 5.0, the MRU Path Selection Policy (PSP) is normally selected but some storage arrays need to use Fixed. 31. What is swap size? When you power on a VM, a memory swap file is created that can be used in lieu of physical host memory if an ESX host exhausts all of its physical memory because it is overcommitted. These files are created equal in size to the amount of memory assigned to a VM, minus any memory reservations (default is 0) that a VM may have set on it (i.e., a 4 GB VM with a 1 GB reservation will have a 3 GB vswp file created). 32. What is ballooning? Ideally, a VM from which memory has been reclaimed should perform as if it had been configured with less memory. ESX Server uses a ballooning technique to achieve such predictable performance by coaxing the guest OS into cooperating with it when possible. When the ESX host’s machine memory is scarce or when a VM hits a Limit, The kernel needs to reclaim memory and prefers ballooning over swapping. The balloon driver is installed inside the guest OS as part of the VMware Tools installation and is also known as the vmmemctl driver. When the ESX kernel wants to reclaim memory, it instructs the balloon driver to inflate. The balloon driver then requests memory from the guest OS. When there is enough memory available, the guest OS will return memory from its “free” list. When there isn’t enough memory, the guest OS will have to use its own memory management techniques to decide which particular pages to reclaim and if necessary page them out to its swap- or page-file. In the background, the ESX kernel frees up the machine memory page that corresponds to the physical machine memory page allocated to the balloon driver. When there is enough memory reclaimed, the balloon driver will deflate after some time returning physical memory pages to the guest OS again. This process will also decrease the Host Memory Usage parameter Ballooning is only effective it the guest has available space in its swap- or page-file, because used memory pages need to be swapped out in order to allocated the page to the balloon driver. Ballooning can lead to high guest memory swapping. 33. What is thin provisioning? When creating a virtual disk file, by default VMware ESXi/ESX uses a thick type of virtual disk. The thick disk pre-allocates all of the space specified during the creation of the disk. For example, if you create a 10 megabyte disk, all 10 megabytes are pre-allocated for that virtual disk. In contrast, a thin virtual disk does not pre-allocate all of the space. Blocks in the VMDK file are not allocated and backed by physical storage until they are written during the normal

course of operation. A read to an unallocated block returns zeroes, but the block is not backed with physical storage until it is written. 34. What is FT? Fault Tolerance (FT) is a new feature in vSphere that takes VMware’s High Availability technology to the next level by providing continuous protection for a virtual machine (VM) in case of a host failure. It is based on the Record and Replay technology that was introduced with VMware Workstation that lets you record a VM’s activity and later play it back. The feature works by creating a secondary VM on another ESX host that shares the same virtual disk file as the primary VM and then transferring the CPU and virtual device inputs from the primary VM (record) to the secondary VM (replay) via a FT logging NIC so it is in sync with the primary and ready to take over in case of a failure. While both the primary and secondary VMs receive the same inputs, only the primary VM produces output such as disk writes and network transmits. The secondary VM’s output is suppressed by the hypervisor and is not on the network until it becomes a primary VM, so essentially both VMs function as a single VM. 35. What is difference between HA and FT? VMware Fault Tolerance is a high-availability feature that can be used within a VMware High Availability cluster. However, high availability is not synonymous with fault tolerance; there are meaningful differences between the two terms. Each setup requires different available resources and will affect virtual machines differently. The key difference between VMware's Fault Tolerance (FT) and High Availability (HA) products is interruption to virtual machine (VM) operation in the event of an ESX/ESXi host failure. Fault-tolerant systems instantly transition to a new host, whereas high-availability systems will see the VMs fail with the host before restarting on another host. VMware High Availability VMware High Availability should be used to maintain uptime on important but non-missioncritical VMs. While HA cannot prevent VM failure, it will get VMs back up and running with very little disturbance to the virtual infrastructure. Consider the value of HA for host failures that occur in the early hours of the morning, when IT is not immediately available to resolve the problem. In addition to tending to VMs during ESX/ESXi host failure, VMware High Availability can monitor and restart a VM, ensuring the machine is capable of restarting on a new host with enough resources. VMware Fault Tolerance VMware FT instantly moves VMs to a new host via vLockstep, which keeps a secondary VM in sync with the primary, ready to take over at any second, like a Broadway understudy. The VM's instructions and instruction sequence are the actor's lines, which pass to the

understudy on a dedicated server backbone network. Heartbeats ping between the star and understudy on this backbone as well, for instantaneous detection of a failure. 36. Difference between HA and vMotion? VMotion and HA are not related and are not dependents of each other. DRS have a dependency on vMotion, but not HA. HA is used in the event that a hosts fails you can have your virtual machines restart on another host in the cluster. vMotion allows you to move a virtual machine from one host to another while it is running without service interruption. Ideally you will utilize vMotion, HA and DRS within your cluster to achieve a well-balanced VI environment. 37. What is Deference between ESX and ESXi? VMware ESX Architecture. In the original ESX architecture, the virtualization kernel (referred to as the vmkernel) is augmented with a management partition known as the console operating system (also known as COS or service console). The primary purpose of the Console OS is to provide a management interface into the host. Various VMware management agents are deployed in the Console OS, along with other infrastructure service agents (e.g. name service, time service, logging, etc). In this architecture, many customers deploy other agents from 3rd parties to provide particular functionality, such as hardware monitoring and system management. Furthermore, individual admin users log into the Console OS to run configuration and diagnostic commands and scripts. VMware ESXi Architecture. In the ESXi architecture, the Console OS has been removed and all of the VMware agents run directly on the vmkernel. Infrastructure services are provided natively through modules included with the vmkernel. Other authorized 3rd party modules , such as hardware drivers and hardware monitoring components, can run in vmkernel as well. Only modules that have been digitally signed by VMware are allowed on the system, creating a tightly locked-down architecture. Preventing arbitrary code from running on the ESXi host greatly improves the security of the system.

Capability

VMware ESX

VMware ESXi

Service Console

Service Console is a standard Linux environment through which a user has privileged access to the VMware ESX kernel. This Linux-based privileged access allows you to manage your environment by installing agents and drivers and executing scripts

VMware ESXi is designed to make the server a computing appliance. Accordingly, VMware ESXi behaves more like firmware than traditional software. To provide hardware-like security and reliability, VMware ESXi does not support a privileged access

and other Linux-environment code. CLI-Based Configuration

VMware ESX Service Console has a host CLI through which VMware ESX can be configured. VMware ESX can also be configured using vSphere CLI (vCLI).

Scriptable Installation

VMware ESX supports scriptable installations through utilities like KickStart.

Boot from SAN

VMware ESX supports boot from SAN. Booting from SAN requires one dedicated LUN per server.

environment like the Service Console for management of VMware ESXi. The vSphere CLI (vCLI) is a remote scripting environment that interacts with VMware ESXi hosts to enable host configuration through scripts or specific commands. It replicates nearly all the equivalent COS commands for configuring ESX. VMware ESXi Installable does not support scriptable installations in the manner ESX does, at this time. VMware ESXi does provide support for post installation configuration script using vCLI-based configuration scripts. VMware ESXi may be deployed as an embedded hypervisor or installed on a hard disk. In most enterprise settings, VMware ESXi is deployed as an embedded hypervisor directly on the server. This operational model does not require any local storage and no SAN booting is required because the hypervisor image is directly on the server.

Serial Cable

VMware ESX supports

The installable version of VMware ESXi does not support booting from SAN. VMware ESXi does not

Connectivity

interaction through directattached serial cable to the VMware ESX host.

support interaction through direct-attached serial cable to the VMware ESXi host at this time.

SNMP

VMware ESX supports SNMP.

VMware ESXi supports SNMP when licensed with vSphere Essentials, vSphere Essential Plus, vSphere Standard, vSphere Advanced, vSphere Enterprise, or vSphere Enterprise Plus.

Active Directory Integration

VMware ESX supports Active Directory integration through third-party agents installed on the Service Console.

HW Instrumentation

Service Console agents provide a range of HW instrumentation on VMware ESX.

The free version of VMware ESXi does not support SNMP. VMware ESXi does not support Active Directory authentication of local users at this time. VMware ESXi provides HW instrumentation through CIM Providers. Standards-based CIM Providers are distributed with all versions of VMware ESXi. VMware partners include their own proprietary CIM Providers in customized versions of VMware ESXi. These customized versions are available either from VMware’s web site or the partner’s web site, depending on the partner. Remote console applications like Dell DRAC, HP iLO, IBM RSA, and FSC iRMC S2 are supported with ESXi.

Software Patches and Updates

VMware ESX software patches and upgrades behave like traditional Linux based patches and upgrades. The installation of a software patch or upgrade may require multiple system boots as the patch or upgrade may have dependencies on previous patches or upgrades.

VMware ESXi patches and updates behave like firmware patches and updates. Any given patch or update is all-inclusive of previous patches and updates. That is, installing patch version “n” includes all updates included in patch versions n-1, n-2, and so forth. Furthermore, third party components such as OEM CIM providers can be updated independently of the base ESXi component, and vice versa.

VI Web Access

VMware ESX supports managing your virtual machines through VI Web Access. You can use the VI Web Access to connect directly to the ESX host or to the VMware Infrastructure Client.

VMware ESXi does not support web access at this time.

Diagnostics and Troubleshooting

VMware ESX Service Console can be used to issue commands that can help diagnose and repair support issues with the server.

VMware ESXi has several ways to enable support of the product: Remote command sets such as the vCLI include diagnostic commands such as vmkfstools, resxtop, and vmware-cmd. The console interface of VMware ESXi (known as the DCUI or Direct Console User Interface) has functionality to help repair the system, including restarting of all management agents.

Tech Support Mode, which allows low-level access to the system so that advanced diagnostic commands can be issues. 38. Difference between vSphere 4.1 and vSphere 5? Features

vSphere 4.1

vSphere 5.0

ESX & ESXi

Only ESXi

Yes VMA 4.1

Yes VMA 5

HA Agent

AAM Automatic Availability Manager

FDM Fault Domain Manager

HA Host Approach

Primary & Secondary

Master & Slave

Management N/W

Management N/W and Storage communication

/etc/opt/vmware/AAM

/etc/opt/vmware/FDM

Yes

NO

NO

boot systems from hard drives, CD/DVD drives, or USB media

Not Available

Yes

Available

Available

VMDK Affinity & AntiAffinity

Not Available

Available

Profile driven storage

Not Available

Available

VMFS-3

VMFS-5

Not Available

Available

Hypervisor VMA

HA Failure Detection HA Log File DNS Dependent on DNS

Host UEFI boot support Storage DRS VM Affinity & Anti-Affinity

VMFS 5 VSphere Storage Appliance

Can be only done via Cli using ESXCLI

Configure dependent hardware iSCSI and software iSCSI adapters along with the network configurations and port binding in a single dialog box using the vSphere Client.

Storage I/O control for NFS

Fiber Channel

Fiber Channel & NFS

Storage Vmotion Snapshot support

VM with Snapshot cannot be migrated using Storage vMotion

VM with Snapshot can be migrated using Storage vMotion

Swap to SSD

NO

Yes

Network I/O control

Yes

Yes with enhancement

ESXi firewall

Not Available

Yes

vCenter Linux Support

Not Available

vCenter Virtual Appliance

vSphere Full Client

Yes

Yes

vSphere Web Client

Yes

yes with lot of improvements

7

8

Virtual CPU per VM

8 vCpu

32 vCpu

Virtual Machine RAM

255 GB

1 TB of vRAM

VM Swapfile size

255 GB

1 TB

Support for Client connected USB

Not Available

Yes

Non Hardware Accelerated 3D grpahics support

Not Available

Yes

UEFI Virtual BIOS

Not Available

Yes

4.1

5

Mutlicore vCpu

Not Available

Yes configure at VM setting

MAC OS Guest Support

Not Available

Apple Mac OS X Server 10.6

Smart card reader support for VM

Not Available

Yes

Iscsi Port Binding GUI

VM Hardware Version 8

VMware Tools Version

Auto Deploy

Not Available

Yes

Image Builder

Not Available

Yes

VM's per host

320

512

Max Logical Cpu per Host

160

160

RAM per Host

1 TB

2 TB

800 MB

Not Applicable (NO SC)

256

256

Round-trip latencies of up to 5 milliseconds.

Round-trip latencies of up to 10 milliseconds. This provides better performance over long latency networks

Moving VM Files using moving to using dirty block tracking

Moving VM Files using I/O mirroring with better enhancements

Virtual Distributed Switch

Yes

Yes with more enhancements like deeper view into virtual machine traffic through Netflow and enhances monitoring and troubleshooting capabilities through SPAN and LLDP

USB 3.0 Support

NO

Yes

Host Per vCenter

1000

1000

Powered on virtual machines per vCenter Server

10000

10000

Vmkernel

64-bit

64-bit

Service Console

64-bit

Not Applicable (NO SC)

MAX RAM for Service Console LUNS per Server

Metro Vmotion

Storage Vmotion

Licensing

vSphere Essentials vSphere Essentials Plus vSphere Standard vSphere Advanced vSphere Enterprise vSphere Enterprise Plus

vSphere Essentials vSphere Essentials Plus vSphere Standard vSphere Enterprise vSphere Enterprise Plus

39. Describe vSphere 5 Licensing?

vSphere 5 has changed entitlements around CPU cores and memory use. vSphere 5 has also introduced a small change to the entitlement process around what is known as virtual memory or vRAM.

40. What is vRAM pool? vRAM or virtual RAM is the total memory configured to a virtual machine; Available pooled vRAM is equal to the sum total of vRAM entitlements for all VMware

vSphere licenses of a single edition, managed by a single instance of VMware vCenter Server or by multiple instances of VMware vCenter Server in Linked Mode.

41. What difference between VMFS 3 and VMFS 5?

VMFS3 Volume size 64TB Raw device mapping size (virtual compatibility) 2TB minus 512 bytes Raw Device Mapping size (physical compatibility) 2TB minus 512 bytes Block size 8MB File size (1MB block size) 256GB File size (2MB block size) 512GB File size (4MB block size) 1TB File size (8MB block size) 2TB minus 512 bytes Files per volume Approximately 30,720 VMFS5 Volume size 64TB Raw Device Mapping size (virtual compatibility) 2TB minus 512 bytes Raw Device Mapping size (physical compatibility) 64TB Block size 1MB File size 2TB minus 512 bytes Files per volume Approximately 130,690

42. How to enable Tech Support mode in ESX 3.5? ESXi 3.5 does ship with the ability to run SSH, but this is disabled by default (and is not supported). If you just need to access the console of ESXi, then you only need to perform steps 1 - 3. 1. At the console of the ESXi host, press ALT-F1 to access the console window. 2. Enter unsupported in the console and then press Enter. You will not see the text you type in. 3. If you typed in unsupported correctly, you will see the Tech Support Mode warning and a password prompt. Enter the password for the root login. You should then see the prompt of ~ #. 43. How to enable Tech Support mode in ESXi 4.1? Tech Support Mode (TSM) provides a command-line interface that can be used by the administrator to troubleshoot and correct abnormal conditions on VMware ESXi hosts. TSM can be accessed in two ways:

 

Logging in directly on the console of the ESXi server. Logging in remotely via SSH.

44. How to enable Tech Support mode using CLI? To enable/disable and start/stop the local ESXi Shell or local TSM from the local command line on the ESXi host: 

To start the ESXi Shell or local TSM, run the command: ESXi 5.x – vim-cmd hostsvc/start_esx_shell ESXi 4.1 – vim-cmd hostsvc/start_local_tsm



To disable the ESXi Shell or local TSM, run the command: ESXi 5.x – vim-cmd hostsvc/disable_esx_shell ESXi 4.1 – vim-cmd hostsvc/disable_local_tsm



To stop the ESXi Shell or local TSM, run the command: ESXi 5.x – vim-cmd hostsvc/stop_esx_shell ESXi 4.1 – vim-cmd hostsvc/stop_local_tsm

45. What are the files that make a Virtual Machine? .vmx - Virtual Machine Configuration File .nvram - Virtual Machine BIOS .vmdk - Virtual Machine Disk file .vswp - Virtual Machine Swap File .vmsd - Virtual Machine Snapshot Database .vmsn - Virtual Machine Snapshot file .vmss - Virtual Machine Suspended State file .vmware.log - Current Log File .vmware-#.log - Old Log file vswp file is only present when the VM is powered on and the .vmss file is only present when a VM is suspended. 46. What is the .nvram file? This small file contains the Phoenix BIOS that is used as part of the boot process of the virtual machine. It is similar to a physical server that has a BIOS chip that lets you set hardware configuration options. A VM also has a virtual BIOS that is contained in the NVRAM file. The BIOS can be accessed when a VM first starts up by pressing the F2 key. Whatever changes are made to the hardware configuration of the VM are then saved in the NVRAM file. This file is in binary format and if deleted it will be automatically recreated when a VM is powered on.

47. What is the .vmx file? This file contains all of the configuration information and hardware settings of the virtual machine. Whenever you edit the settings of a virtual machine, all of that information is stored in text format in this file. This file can contain a wide variety of information about the VM, including its specific hardware configuration (i.e., RAM size, network interface card info, hard drive info and serial/parallel port info), advanced power and resource settings, VMware tools options, and power management options. While you can edit this file directly to make changes to a VM's configuration it is not recommended that you do so unless you know what you are doing. If you do make changes directly to this file, it's a very good idea to make a backup copy of this file first. 48. What are VMDK files? All virtual disks are made up of two files, a large data file equal to the size of the virtual disk and a small text disk descriptor file, which describes the size and geometry of the virtual disk file. The descriptor file also contains a pointer to the large data file as well as information on the virtual disks drive sectors, heads, cylinders and disk adapter type. In most cases these files will have the same name as the data file that it is associated with (i.e., myvm_1.vmdk and myvm_1-flat.vmdk). You can match the descriptor file to the data file by checking the Extent Description field in this file to see which –flat, -rdm or – delta file is linked to it. An example disk descriptor file is shown below: The three different types of virtual disk data files that can be used with virtual machines are covered below: 

The –flat.vmdk file This is the default large virtual disk data file that is created when you add a virtual hard drive to your VM that is not an RDM. When using thick disks, this file will be approximately the same size as what you specify when you create your virtual hard drive. One of these files is created for each virtual hard drive that a VM has configured, as shown in the examples below.



The –delta.vmdk file

These virtual disk data files are only used when snapshots are created of a virtual machine. When a snapshot is created, all writes to the original –flat.vmdk are halted and it becomes read-only; changes to the virtual disk are then written to these –delta files instead. The initial size of these files is 16 MB and they are grown as needed in 16 MB increments as changes are made to the VM's virtual hard disk. Because these files are a bitmap of the changes made to a virtual disk, a single –delta.vmdk file cannot exceed the size of the original –flat.vmdk file. A delta file will be created for each snapshot that you create for a VM and their file names will be incremented numerically (i.e., myvm000001-delta.vmdk, myvm-000002-delta.vmdk). These files are automatically deleted when the snapshot is deleted after they are merged back into the original –flat.vmdk file.



The -rdm.vmdk file

This is the mapping file for the RDM that manages mapping data for the RDM device. The mapping file is presented to the ESX host as an ordinary disk file, available for the usual file system operations. However, to the virtual machine the storage virtualization layer presents the mapped device as a virtual SCSI device. The metadata in the mapping file includes the location of the mapped device (name resolution) and the locking state of the mapped device. If you do a directory listing you will see that these files will appear to take up the same amount of disk space on the VMFS volume as the actual size of the LUN that it is mapped to, but in reality they just appear that way and their size is very small. One of these files is created for each RDM that is created on a VM.

49. What is the .vswp file? When you power on a VM, a memory swap file is created that can be used in lieu of physical host memory if an ESX host exhausts all of its physical memory because it is overcommitted. These files are created equal in size to the amount of memory assigned to a VM, minus any memory reservations (default is 0) that a VM may have set on it (i.e., a 4 GB VM with a 1 GB reservation will have a 3 GB vswp file created). These files are always created for virtual machines but only used if a host exhausts all of its physical memory. As virtual machine memory that is read/written to disk is not as fast as physical host RAM, your VMs will have degraded performance if they do start using this file. These files can take up quite a large amount of disk space on your VMFS volumes, so ensure that you have adequate space available for them, as a VM will not power on if there is not enough room to create this file. These files are deleted when a VM is powered off or suspended. 50. What is the .vmss file? This file is used when virtual machines are suspended and is used to preserve the memory contents of the VM so it can start up again where it left off. This file will be approximately the same size as the amount of RAM that is assigned to a VM (even empty memory contents are written). When a VM is brought out of a suspend state, the contents of this file are written back into the physical memory of a host server, however the file is not automatically deleted until a VM is powered off (an OS reboot won't work). If a previous suspend file exists when a VM is suspended again, this file is re-used instead of deleted and re-created. If this file is deleted while the VM is suspended, then the VM will start normally and not from a suspended state. 51. What is the .vmsd file? This file is used with snapshots to store metadata and other information about each snapshot that is active on a VM. This text file is initially 0 bytes in size until a snapshot is created and is updated with information every time snapshots are created or deleted. Only one of these files exists regardless of the number of snapshots running, as they all update this single file. The snapshot information in this file consists of the name of the VMDK and vmsn file used by each snapshot, the display name and description, and the UID of the snapshot. Once your snapshots are all deleted this file retains old snapshot information but increments the snapshot UID to be used with new snapshots. It also renames the first snapshot to "Consolidate Helper," presumably to be used with consolidated backups. 52. What is the .vmsn file? This file is used with snapshots to store the state of a virtual machine when a snapshot is taken. A separate .vmsn file is created for every snapshot that is created on a VM and is automatically deleted when the snapshot is deleted. The size of this file will vary based on whether or not you choose to include the VM's memory state with your snapshot. If you do choose to store the memory state, this file will be slightly larger than the amount of RAM that has been assigned to the VM, as the entire memory contents,

including empty memory, is copied to this file. If you do not choose to store the memory state of the snapshot then this file will be fairly small (under 32 KB). This file is similar in nature to the .vmss that is used when VMs are suspended. 53. What is the .log file? These are the files that are created to log information about the virtual machine and are oftentimes used for troubleshooting purposes. There will be a number of these files present in a VM's directory. The current log file is always named vmware.log and up to six older log files will also be retained with a number at the end of their names (i.e., vmware-2.log). A new log file is created either when a VM is powered off and back on or if the log file reaches the maximum defined size limit. The amount of log files that are retained and the maximum size limits are both defined as VM advanced configuration parameters (log.rotateSize and log.keepOld). 54. What is the .vmxf file? This file is a supplemental configuration file that is not used with ESX but is retained for compatibility purposes with Workstation. It is in text format and is used by Workstation for VM teaming where multiple VMs can be assigned to a team so they can be powered on or off, or suspended and resumed as a single object. 55. How to know registered VM on Host using CLI? 

List All VMs on the Host # vim-cmd vmsvc/getallvms



Get Information for a Specific VM # vim-cmd vmsvc/get.guest 30



Get Configuration for a Specific VM # vim-cmd vmsvc/get.config 30



Get Summary for a Specific VM # vim-cmd vmsvc/get.summary 30



Get Current Power State of a Specific VM # vim-cmd vmsvc/power.getstate 30



Power On a Specific VM # vim-cmd vmsvc/power.on 30



Power Off a Specific VM (Hard) # vim-cmd vmsvc/power.off 30



Shutdown a Specific VM # vim-cmd vmsvc/power.shutdown 30



Reboot a Specific VM

# vim-cmd vmsvc/power.reset 30 

List a Specific VM’s Snapshots # vim-cmd vmsvc/get.snapshot 30



Unregister a VM from a ESX Host # vim-cmd vmsvc/unregister 30



Register a VM on a ESX Host # vim-cmd solo/registervm path/to/.vmx

56. How many Hosts can we have in a Cluster in vCenter 5? HA does not limit the number of hosts in a cluster. Using more hosts in a cluster results in less overhead. (N+1 for 8 hosts vs N+1 for 32 hosts) Big clusters are good for DRS. More hosts equals more scheduling opportunities. Max number of hosts accessing a file = 8 .This is a constraint in an environment using linked clones like VMware View, vCloud Director. Max values in general (256 LUNs, 1024 Paths, 512 VMs per host, 3000 VMs per cluster) 57. What are Resource Pool, Allocation and Priority? A VMware ESX Resource pool is a pool of CPU and memory resources. Inside the pool, resources are allocated based on the CPU and memory shares that are defined. This pool can have associated access control and permissions. 58. What is PVLAN? A private VLAN is a technique in computer networking where a VLAN contains switch ports that are restricted, such that they can only communicate with a given "uplink". The restricted ports are called "private ports". Each private VLAN typically contains many private ports, and a single uplink. The uplink will typically be a port (or link aggregation group) connected to a router, firewall, server, provider network, or similar central resource. The switch forwards all frames received on a private port out the uplink port, regardless of VLAN ID or destination MAC address. Frames received on an uplink port are forwarded in the normal way (i.e., to the port hosting the destination MAC address, or to all VLAN ports for unknown destinations or broadcast frames). "Peer-to-peer" traffic is blocked. Note that while private VLANs provide isolation at the data link layer, communication at higher layers may still be possible. 59. Which file is created during vMotion? A second vswp file gets created during a VMotion.

60. Which one ver. of MS SQL required for Windows vCenter? Microsoft SQL Server 2008 Standard (R2) - 64-bit Microsoft SQL Server 2008 Standard (R2) - 32-bit Microsoft SQL Server 2008 Express (R2) - 64-bit Microsoft SQL Server 2008 Express (R2 SP1) - 64-bit Microsoft SQL Server 2008 Enterprise (R2) - 64-bit Microsoft SQL Server 2008 Enterprise (R2) - 32-bit Microsoft SQL Server 2008 Datacenter Edition (SP2) -64-bit Microsoft SQL Server 2008 Standard Edition (SP2) -32-bit 61. What you understand by Appliances? A virtual appliance is a virtual machine image designed to run on a virtualization platform (e.g., VirtualBox, Xen, VMware Workstation, Parallels Workstation). Virtual appliances are a subset of the broader class of software appliances. Installation of a software appliance on a virtual machine creates a virtual appliance. Like software appliances, virtual appliances are intended to eliminate the installation, configuration and maintenance costs associated with running complex stacks of software. 62. What are VMware vCloud Director 1.5 Config Maximums? Type: Virtual machines per vCloud Director Limit: 20000 Description: The maximum number of virtual machines that may be resident in a vCloud instance. Type: Powered on VMs per vCloud Director Limit: 10000 Description: Number of concurrently powered on virtual machines permitted per vCloud instance. Type: Virtual machines per vApp Limit: 128 Description: The maximum number of virtual machines that can reside in a single vApp. Type: Hosts per vCloud Director Limit: 2000 Description: Number of hosts that can be managed by a single vCloud instance. Type: vCenter Servers per vCloud Director Limit: 25 Description: Number of vCenter servers that can be managed by a single vCloud instance. Type: Users per vCloud Director Limit: 10000

Description: The maximum number of users that can be managed by a single vCloud instance. Type: Organizations per vCloud Director Limit: 10000 Description: The maximum number of organizations that can be created in a single vCloud instance. Type: vApps per organization Limit: 500 Description: The maximum number of vApps that can be deployed in a single organization. Type: Virtual datacenters per vCloud Director Limit: 5000 Description: The maximum number of virtual datacenters that can be created in a single vCloud instance. Type: Datastores per vCloud Director Limit: 1024 Description: Number of datastores that can be managed by a single vCloud instance. Type: Networks per vCloud Director Limit: 7500 Description: The maximum number of logical networks that can be deployed in a single vCloud instance. Type: Catalogs per vCloud Director Limit: 1000 Description: The maximum number of catalogs that can be created in a single vCloud instance. Type: Media Items per vCloud Director Limit: 1000 Description: The maximum number of media items which can be created in a single vCloud instance. 63. Explain the entire process of P2V conversion? Below are the steps you should take to prepare your server for conversion. 1) Install the Converter application on the server being migrated. If you are using the Enterprise version you can do this remotely, but my preference is to install Converter directly on to the server a potential complication caused by introducing another PC in the conversion process. If you have many machines to convert this is not always practical. The Converter application consists of two parts, the Agent component (Windows service) and the Manager component (front end GUI). If you are running

this on the server directly you need both components. Otherwise if you are running it remotely only the Agent component is needed. 2) Once you install the application on the server a reboot will be required if the server OS is Windows NT 4.0 or 2000. This is because a special driver is installed for the cloning process on those OS's, Windows XP and 2003 utilize the Volume Shadow Copy service instead. Also, it's best to use a local administrator account when logging into the server to install the application. 3) The following Windows services must be running for Converter to work properly: Workstation, Server, TCP/IP Netbios Helper and Volume Shadow Copy (Windows XP/2003, can be set to manual, just not disabled). Also, disable Windows Simple File Sharing if your source server is running Windows XP. 4) Make sure the VMware Converter Windows service is running. 5) Ensure you have at least 200 MB free on your source server's C drive. Mirrored or striped volumes across multiple disks should be broken; hardware RAID is OK since it is transparent to the operating system. Converter sometimes has issues converting dynamic disks, if you experience problems with them, then cold clone instead. 6) Disable any antivirus software running on the source server. 7) Shutdown any applications that are not needed on the server. 8) Run chkdsk and defragment your source server's hard disks. 9) Clean-up any temporary and unnecessary files on the source server. The less data that needs to be copied the better. This only applies when utilizing file level cloning (more on that later). 10) Keep users off the server while cloning. Disable remote desktop and any shares if possible. 11) Ensure required TCP/UDP ports are opened between the source server and VirtualCenter (VC) and VMware ESX. Even if you select VirtualCenter as your destination, the ports still need to be opened to the ESX server you choose. The source server first contacts VC to create the VM and then ESX to transfer the data to. Required ports are 443 and 902 (source to ESX/VC) and 445 and 139 (converter to source and source to Workstation/Server). These ports need to be opened on both OS firewalls and any network firewalls sitting between your source and destination servers. 12) Ensure your network adapter speed/duplex matches your physical switch setting. This can have a dramatic effect on your conversion speed. When cold cloning it's best to set your physical switch port to Auto/Auto since this is what the Windows PE ISO will default to. 13) If importing a VM or physical image the Windows version of the server running Converter must be equal to or greater than the source. So, if your source is Windows 2003, the server running Converter cannot be Windows 2000. 14) For cold cloning, the minimum memory requirement is 264 MB (will not work with less than this amount), the recommended memory is 364 MB. Converter also utilizes a RAM disk if you have at least 296 MB of memory available.

Making the conversion With these steps complete, we're ready to get started. Start the Converter Manager application and click the Import Machine button to start the Converter Wizard. Select your Source server, in this example we will choose Physical Computer. Select This Local Machine if running Converter on the source server, otherwise enter the hostname/IP and login information of the server to be converted. At the Source Data screen you have the option to select your disk volumes and re-size then larger or smaller if needed. Make sure you do not select any small utility partitions created by your hardware installation. What you decide here will determine which disk cloning method is used to copy your source data. If you do not change your drive sizes or increase them, then a block-level clone will be performed. If you decrease the size of your drives by any amount then a file-level clone will be performed instead. When a block-level clone is performed, data is transferred from the source server disk to the destination server disk block-by-block. This method is faster but results in more data being copied (even empty disk blocks are copied). When a file-level clone is performed, data is instead transferred file-by-file, which is slower but results in less data being copied. So if you only have 5 GB of data on a 40 GB drive, then only the 5 GB is copied. It's a trade-off between the two methods between faster transfer speed versus reduced data size which often results in about the same time to copy the data. One potential caveat with the file-level copy is if you have a server with a huge amount of small files, it can take days to copy the data, and will sometimes fail. I experienced a server with 200,000+ 2 K files in one directory which brought the conversion to a crawl. Once I removed these files it completed in a few hours. Next choose your destination server which is typically VirtualCenter (VC)/ESX. If you have a VC server managing a destination ESX server, it is best to choose the VC server first. Continue entering a VM name, host and datastore; at the Networks screen you can select one or more NIC's and networks to connect to. My preference is to first connect the VM to an Internal Only vSwitch so it is isolated from the source server and I can power it on while the source server is still up. Once I verify that the newly created VM is functioning properly and I go through the post-clone procedures, I shut down the source server and move the VM to the same network that the source server was on. Finally select whether or not to install VMware Tools, enter any OS customization if necessary, select whether or not to power on the VM right after the conversion completes and click the Finish button to start the conversion process. Once the conversion starts you can monitor the progress in the task progress window. 64. Difference between hot clone and cold clone? Hot cloning: Convert physical machines while they are still running Cold cloning: Convert physical machines using a BootCD (download from VMware site)

65. What is VMware VMotion & Storage VMotion (SVMotion)? With VMotion, VM guests are able to move from one ESX Server to another with no downtime for the users. What is required is a shared SAN storage system between the ESX Servers and a VMotion license. Storage VMotion (or SVMotion) is similar to VMotion in the sense that it moves VM guests without any downtime. However, what SVMotion also offers is the capability to move the storage for that guest at the same time that it moves the guest. Thus, you could move a VM guest from one ESX server’s local storage to another ESX server’s local storage with no downtime for the end users of that VM guest. 66. What are the three port groups present in ESX4 server networking 1. Virtual Machine Port Group - Used for Virtual Machine Network 2. Service Console Port Group - Used for Service Console Communications 3. VMKernel Port Group - Used for VMotion, iSCSI, NFS Communications 67. What is the use of a Port Group? The port group segregates the type of communication. 68. What is the type of communications which requires an IP address for sure? Service Console and VMKernel (VMotion and iSCSI), these communications does not happen without an ip address (Whether it is a single or dedicated) 69. In the ESX Server licensing features VMotion License is showing as Not used, why? Even though the license box is selected, it shows as "License Not Used" until, you enable the VMotion option for specific vSwitch 70. How the Virtual Machine Port group communication works? All the vm's which are configured in VM Port Group are able to connect to the physical machines on the network. So this port group enables communication between vSwitch and Physical Switch to connect vm's to Physical Machine's 71. What is a VLAN? A VLAN is a logical configuration on the switch port to segment the IP Traffic. For this to happen, the port must be trunked with the correct VLAN ID. 72. Does the vSwitches support VLAN Tagging? Why? Yes, The vSwitches support VLAN Tagging, otherwise if the virtual machines in an esx host are connected to different VLANS, we need to install a separate physical nic

(vSwitch) for every VLAN. That is the reason vmware included the VLAN tagging for vSwitches. So every vSwitch supports upto 1016 ports, and BTW they can support 1016 VLANS if needed, but an ESX server doesn’t support that many VM’s. :) 73. What is Promiscuous Mode on vSwitch ? What happens if it sets to accept? Accept: Placing a guest adapter in promiscuous mode causes it to detect all frames passed on the vSphere standard switch that are allowed under the VLAN policy for the port group that the adapter is connected to. Reject: Placing a guest adapter in promiscuous mode has no effect on which frames are received by the adapter. 74. What is MAC address Changes? What happens if it is set to accept? Accept: Changing the MAC address from the Guest OS has the intended effect: frames to the new MAC address are received. Reject: If you set the MAC Address Changes to Reject and the guest operating system changes the MAC address of the adapter to anything other than what is in the .vmx configuration file, all inbound frames are dropped. If the Guest OS changes the MAC address back to match the MAC address in the .vmx configuration file, inbound frames are passed again. 75. What is Forged Transmits? What happens if it is set to accept? Accept — No filtering is performed and all outbound frames are passed. Reject — Any outbound frame with a source MAC address that is different from the one currently set on the adapter are dropped. 76. What are the core services of VC? VM provisioning, Task Scheduling and Event Logging 77. Can we do vMotion between two datacenters? If possible how it will be? Yes we can do vMotion between two datacenters, but the mandatory requirement is the VM should be powered off. 78. What is VC agent? And what service it is corresponded to? What are the minimum requirements for VC agent installation? VC agent is an agent installed on ESX server which enables communication between VC and ESX server. The daemon associated with it is called vmware-hostd , and the service which corresponds to it is called as mgmt-vmware, in the event of VC agent failure just restart the service by typing the following command at the service console

79. "service mgmt-vmware restart " 80. How can you edit VI Client Settings and VC Server Settings? Click Edit Menu on VC and Select Client Settings to change VI settings Click Administration Menu on VC and Select VC Management Server Configuration to Change VC Settings 81. What are the files that make a Virtual Machine? .vmx - Virtual Machine Configuration File .nvram - Virtual Machine BIOS .vmdk - Virtual Machine Disk file .vswp - Virtual Machine Swap File .vmsd - Virtual Machine Snapshot Database .vmsn - Virtual Machine Snapshot file .vmss - Virtual Machine Suspended State file .vmware.log - Current Log File .vmware-#.log - Old Log file 82. What are the devices that can be added while the virtual Machine running.

In VI 3.5 we can add Hard Disk and NIC's while the machine running. In vSphere 4.0 we can add Memory and Processor along with HDD and NIC's while the machine running 83. How to set the time delay for BIOS screen for a Virtual Machine? Right Click on VM, select edit settings, choose options tab and select boot option, set the delay how much you want. 84. What is a template? We can convert a VM into Template, and it cannot be powered on once its changed to template. This is used to quick provisioning of VM's. 85. What to do to customize the windows virtual machine clone? Copy the sysprep files to Virtual center directory on the server, so that the wizard will take the advantage of it. 86. What to do to customize the linux/unix virtual machine clone? VC itself includes the customization tools, as these operating systems are available as open source. 87. Does cloning from template happen between two datacenters?

Yes. It can, if the template in one datacenter, we can deploy the vm from that template in another datacenter without any problem. 88. What are the common issues with snapshots? What stops from taking a snapshot and how to fix it? If you configure the VM with Mapped LUN's, then the snapshot failed. If it is mapped as virtual then we can take a snapshot of it. If you configure the VM with Mapped LUN's as physical, you need to remove it to take a snapshot. 89. What are the settings that are taken into to consideration when we initiate a snapshot? Virtual Machine Configuration (What hardware is attached to it) State of the Virtual Machine Hard Disk file (To revert back if needed) State of the Virtual Machine Memory (if it is powered on) 90. What are the requirements for Converting a Physical machine to VM? An agent needs to be installed on the Physical machine VI client needs to be installed with Converter Plug-in A server to import/export virtual machines 91. What is VMWare consolidated backup? It is a backup framework, which supports 3rd party utilities to take backups of ESX servers and Virtual Machines. It’s not a backup service. 92. To open the guided consolidation tool, what are the user requirements? The user must be member of administrator, the user should have "Logon as service" privileges - To give a user these privileges, open local sec policy, select Logon as service policy and add the user the user should have read access to AD to send queries 93. Explain the physical topology of Virtual Infrastructure 3 Data Centre? A typical VMware Infrastructure data center consists of basic physical building blocks such as x86 computing servers, storage networks and arrays, IP networks, a management server and desktop clients. 94. How do you configure Clusters, Hosts, and Resource Pools in VI3? A cluster is a group of servers working together closely as a single server, to provide high availability, load balancing and high performance. A host is a single x86 computing server with individual computing and memory resources. Resource pools are allocation of the available resources in to pieces for the proper distribution. 95. What are resource pools & what’s the advantage of implementing them?

A VMware ESX Resource pool is a pool of CPU and memory resources. Inside the pool, resources are allocated based on the CPU and memory shares that are defined. This pool can have associated access control and permissions. Clear management of resources to the virtual machines. 96. What is vApp? A vApp is a container, like a resource pool and can contain one or more virtual machines. A vApp also shares some functionality with virtual machines. A vApp can power on and power off, and can also be cloned. In the vSphere Client, a vApp is represented in both the Host and Clusters view and the VM and Template view. Each view has a specific summary page with the current status of the service and relevant summary information, as well as operations on the service. The distribution format for vApp is OVF. Note: The vApp metadata resides in the vCenter Server's database, so a vApp can be distributed across multiple ESX/ESXi hosts. This information can be lost if the vCenter Server database is cleared or if a standalone ESX/ESXi host that contains a vApp is removed from vCenter Server. You should back up vApps to an OVF package to avoid losing any metadata. 97. Explain why VMware ESX Server is preferred over Virtual Server or Workstation for enterprise implementation? For better resource management as it has a virtualization layer involved in its kernel, which communicates with the hardware directly. 98. Explain the difference between access through Virtual Infrastructure Client (vi client), Web access, Service Console access (ssh)? Using VI Client we can access the ESX server as well as Virtual Center Server also, here we can use unix type of authentication or windows type authentication. But to access the service console, we should use unix type of authentication preferably even though we can access the service console through ad authentication using esxcfg-auth, but it does not support all functions to work on, all the functions are available only with root account which is based on red hat Linux kernel. Using the web access also we can manage virtual center as well as a single host. But all the enterprise features are not supported.

99. What is VMWare Kernel?  

VMWare Kernel is a Proprietary Kenral and is not based on any of the UNIX operating systems, it's a kernel developed by VMWare Company. The VMKernel can't boot it by itself, so that it takes the help of the 3rd party operating system. In VMWare case the kernel is booted by RedHat Linux operating system which is known as service console.



The service console is developed based up on Redhat Linux Operating system; it is used to manage the VMKernel

100. How to restart webaccess service on vmware? service vmware-webaccess restart – this will restart apache tomcat app 101. How to restart ssh service on vmware? service sshd restart 102. How to restart host agent(vmware-hostd) on vmware esx server ESX4: $service mgmt-vmware restart ESX5: $/etc/sbin/services.sh restart 103. What is the path for the struts-config.xml /usr/lib/vmware/webAccess/tomcat/apache-tomcat-5.5.17/webapps/ui/WEB-INF/ 104. How to start the scripted install? esx ks=nfs:111.222.333.444:/data/KS.config ksdevice=eth0 location device name 105. ESX Management Options SSH to the Service Console You can SSH to the console prompt of an ESX server and receive the same Linux text console access as I showed above. Telnet is not allowed. To use this method, the ESX server must be working on the network and you must have an SSH client on your PC to connect. Again, in this mode, you don't get a GUI interface. VMware Virtual Infrastructure (VI) Web Access to the ESX Server This is the VMware VI Web Access interface. The benefit to using this is that you get a GUI client for your ESX server without having to install a client on your local machine. The downside to the web interface is that you can only perform basic ESX functions like controlling existing machines (start/stop/pause) and console remote access. You cannot add new VMs, work with VM storage, or VM networks. Still, this is a great interface if you just need to check the status of your ESX VMs, restart a VM, or use console remote control. VMware Virtual Infrastructure Client (VI Client) to the Server

The benefits to the VI client are that you have full access to do whatever is needed on the ESX Server and you get a GUI client to do it in. The only downside is that you must install the VI client application to do this. However, the installation is negligible and the VI client is the absolute best way to administer your ESX Server. VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server) From this VI VC interface, you can manage all ESX servers, VM storage, VM networks, and more. Virtual Center, of course, is an optional product that requires additional licenses and hardware. 106. Explain advantages and features of VMware Virtual Machine File System (VMFS)? It’s a clustered file system, excellent support for sharing between ESX servers in a cluster. Features Allows access by multiple ESX Servers at the same time by implementing per-file locking. SCSI Reservations are only implemented when LUN Meta data is updated (e.g. file name change, file size change, etc.) Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts. LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS volume on the fly (by spanning multiple VMFS volumes) With ESX/ESXi4 VMFS volumes also can be expanded using LUN expansion Optimize your virtual machine I/O with adjustable volume, disk, file and block sizes. Recover virtual machines faster and more reliably in the event of server failure with Distributed journaling. Limitations Can be shared with up to 32 ESX Servers. Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere). "There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers. For instance, if there is a tree of disks off the same base disk with 40 leaf nodes in the tree, all 40 leaf nodes can be simultaneously run but they can only run on up to 8 ESX hosts."

VMFS-3 limits files to 262,144 (218) blocks, which translates to 256 GB for 1 MB block sizes (the default) up to 2 TB for 8 MB block sizes. 107. What are the types of data stores supported in ESX3.5? iSCSI datastores, FC SAN datastores, Local VMFS, NAS and NFS

108. How can you configure these different types of datastores on ESX3.5? If we have FC cards installed on the esx servers, by going to the storage option, we can scan for the luns. 109. What is VMware Consolidate Backup (VCB)? Explain your work exposure in this area? VMware Consolidated Backup is a backup framework, which enables 3rd party tools to take backups. VCB is used to help you backup your VMware ESX virtual servers. Essentially, VCB is a "backup proxy server". It is not backup software. If you use VCB, you still need backup software. It is commonly installed on its own dedicated Windows physical server. Here are the benefits of VMware's VCB: 1. Centralize backups of VMware ESX Virtual Servers 2. Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level backup available to only Windows guests) 3. Provide image-level backups 4. Prevent you from having to load a backup agent on every Virtual Machine 5. Prevent you from having to shutdown Virtual Machines to get a backup 6. Provides LAN-Free backup because the VCB server is connected to the SAN through your fiber channel adaptor 7. Provides centralized storage of Virtual Server backups on the VCB server, that is then moved to your backup tapes through the 3rd party backup agent you install 8. Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on either the VMware ESX service console or on each virtual machine. 9. Utilizes VMware Snapshots Basically, here is how VCB works: 1. If you are doing a file level backup, VCB does a snapshot of the VM, mounts the snapshot, and allows you to backup that mounted "drive" through VCB to your 3rd party backup software 2. If you are doing an image level backup of the VM, VCB does a snapshot of the VM, copies the snapshot to the VCB server, unsnaps the VM, and allows you to backup the copied snapshot image with your 3rd party backup software. 110. How do you configure VMware Virtual Centre Management Server for HA & DRS? What are the conditions to be satisfied for this setup?

HA & DRS are the properties of a Cluster. A Cluster can be created only when more than one host added, in that case we need to configure HA & DRS as well to provide High Availability and Load balancing between hosts and for the virtual machines. 111. Explain your work related to below terms: VM Provisioning: Virtual Machine Creation. Alarms & Event Management: Alarms are used to know the status of the resource usage for a VM. Events are used monitor the tasks that are taken place on the esx servers or in the virtual center. Task Scheduler: Task scheduler, if you want to schedule a task it will be used, for example if you want move one VM from one host to another host or if you want shutdown/reboot a vm etc. Hardware Compatibility List: what is the hardware that compatible with ESX OS. 112. What SAN or NAS boxes have you configured VMware with? How did you do that? I have configured Microsoft iSCSI software target with VMware. 113. What kind of applications or setups you have on you Virtual Machines? Domain controller, Terminal Server, vCenter, TMG. 114. Have you ever faced ESXi server crashing and Virtual Centre Server crash? How do you know the cause of these crashes in these cases?

115. Will HA work if Virtual Center Server is down? A1) HA continues to work if VC is down - the agents are initially configured by virtual center, but HA operations are controlled by local agents on ESX. VC does NOT monitor the ESX servers for HA. ESX servers monitor each other. DRS do not work while VC is down. A2) For DRS, the config and logic is completely in VC. For HA, only the config is in VC. The logic is in the service consoles, and that's where the reaction is coming from. VC will notice the HA reaction afterwards when it connects to the service consoles the next time. 116. What are the situations which triggers vMotion automatically? Resource Contention between virtual machines (DRS) Distributed power management

117. What is DRS/HA/DPM/dvSwitch/FT/vApps/vSafe/vShields? DRS: Distributed Resource Scheduling HA: High Availability DPM: Distributed Power Management dvSwitch: Distribute vSwitch – It’s a new feature introduced in vSphere4.0 FT: Fault Tolerance for Virtual Machines – it’s a new feature introduced in vSphere4.0 vApps : vApp is a container same as resource pool, but it is having some features of virtual machines, a vApp can be powered on or powered off, and it can be cloned too. vmSafe: VMsafe's application programming interfaces are designed to help third-party vendors create virtualization security products that better secure VMware ESX, vShield Zones is a security tool targets the VMware administrator. vShield: VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual network traffic. This three-part series describes vShield Zones, explains how to install it and provides useful management tips. To begin, let's get started with the basics: what vShield Zones is and how it works. 118. What are the new features introduced in vSphere 4? 1. 64-bit hypervisor - Although not everyone realized it, the hypervisor in ESX Server 3.5 was 32-bit. As a result, ESX Server 3.5 couldn't take full advantage of today's more powerful 64-bit hardware platforms. ESX Server 4.0 uses a native 64-bit hypervisor that provides significant performance and scalability enhancements over the previous versions. However, the new hypervisor does require a 64-bit hardware platform. 2. Increased VM scalability - ESX Server 4.0's new 64-bit architecture provides significant increases in scalability. ESX Server 4.0 supports virtual machines (VMs) with up to 255GB of RAM per VM. In addition, the vSphere 4.0 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM. The other editions support up to 4-way virtual SMP. These gains are available on both Windows and Linux guests. 3. Hot add CPU, RAM, and virtual disks - This important enhancement in vSphere 4.0 is designed to create a dynamic IT infrastructure through the ability to add CPU, RAM, and virtual disks to a running VM. The hot add capability lets you dynamically increase your VMs' performance during periods of high resource demands. 4. Thin provisioning - This feature is nothing new to Microsoft virtualization users; vSphere now offers a thin-provisioning feature that's essentially the equivalent of Hyper-V's dynamic disks. Thin provisioning lets you create and provision a Virtual Hard Disk (VHD), but the host uses only the amount of storage that's actually required by the VM rather than using the VHD's allocated size.

5. VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 4.0. Fault Tolerance works only between two systems. It uses a technology called vLockstep to provide protection from system failure with absolutely no downtime. VMware's vLockstep technology keeps the RAM and the virtual processors of two VMs in sync at the instruction level. 6. vNetwork Distributed Switch—vSphere 4.0's vNetwork Distributed Switch lets you create and share network configurations between multiple servers. The vNetwork Distributed Switch spans multiple ESX Server hosts, letting you configure and manage virtual networks at the cluster level. It also lets you move network configuration and state with a VM when the VM is live migrated between ESX Server hosts. 7. IPv6 support - Another enhancement in vSphere 4.0 is support for IPv6. Many organizations are planning to move to IPv6. vSphere's IPv6 support lets customers manage vCenter Server and ESX Server hosts in mixed IPv4/IPv6 network environments. 8. vApps—vApps essentially lets you manage as a single entity multiple servers that comprise an n-tiered application. Using vApps, you can combine multiple VMs, their interdependencies, and their resource allocations together as a unit. You can manage all the components of the vApps as a single unit, letting you power off, clone, and deploy all the vApps components in the same operations. 9. vSphere Host Update Utility—The new vSphere Host Update Utility lets you centrally update your ESXi and ESX Server 3.0 and later hosts to ESX Server 4.0. The UI displays the status of the remote updates in real time. 10. VMware vShield Zones—VMware's new vShield Zones let customers enforce network access protection between VMs running in the virtual data center. The vShield Zones feature lets you isolate, bridge, and firewall traffic across vCenter deployments. 119. Which are the traffic shaping options available to configure? 

Average Bandwidth is measured in kilobits per second, and is what's allowed across the vSwitch per second from the selected Port Group.

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Peak Bandwidth is also measured in kilobits per second, and identifies the maximum amount that's allowed to pass from the selected Port Group without packets being dropped.



Burst Size is measured in kilobytes. Burst size is a calculation of bandwidth multiplied by time. If there is a period of network resource contention and a network burst from the selected Port Group exceeds the defined Burst Size packets are then dropped in favor of other traffic on the vSwitch. Unless the network traffic queue is not full in which case the packets will just be queued up.

120. What is promiscuous mode? If the promiscuous mode is enabled for a switch, the traffic sent that switch will be visible to all vm’s connected to that switch. I mean, the data will be broadcasted.

121. What makes iSCSI and FC different? Addressing Scheme, iSCSI relies on IP and FC not, and the type of transfer of data also. In FC the data transferred as blocks, in iSCSI the data transferred as files. The cabling also, FC uses Fibre cable and iSCSI uses RJ45. 122. What is the format for iSCSI addressing? IP Address 123. VM's Task Manager Show’s performance normal, but vCenter reports high resource utilization, what is the reason? When it comes to actual (physical) utilization metrics, Virtual Center utilization stats is always more reliable than the guest OS's performance counters, as it has more information to go on; it measures the actual utilization of the process at the vmkernel level, while the guest OS measures its perceived utilization based on how many time slices it thinks it used up on the CPU. 124. What are the different types of memory management tricks available under ESX? http://en.wordpress.com/tag/esx-memory-management/ http://www.cs.northwestern.edu/~fabianb/classes/cs-443-s05/ESX.pps 125. What is vmmemctl? http://pubs.vmware.com/vi3/resmgmt/wwhelp/wwhimpl/common/html/wwhelp.htm?context =resmgmt&file=vc_advanced_mgmt.11.24.html 126. How we can list pNICs & status using command line? ifconfig –a 127. What is resource pool? What is the use of it? A resource pool is a logical abstraction for flexible management of resources. Resource pools can be grouped into hierarchies and used to hierarchically partition available CPU and memory resources. 128. How HA works. VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on into a cluster. Hosts in the cluster are monitored and in the event of a failure, the virtual machines on a failed host are restarted on alternate hosts. 129. Is HA dependent on virtual center?

Only for Install 130. What is the Maximum Host Failure allowed in a cluster? The maximum Configured Failover Capacity that you can set is four. Each cluster has up to five primary hosts and if all fail simultaneously, failover of all hosts might not be successful. However, when you select the “Percentage” admission control policy you can set it to 50% even when you have 32 hosts in a cluster. That means that the amount of failover capacity being reserved equals 16 hosts. Although this is fully supported but there is a caveat of course. The amount of primary nodes is still limited to five. Even if you have the ability to reserve over 5 hosts as spare capacity that does not guarantee a restart. If, for whatever reason, half of your 32 hosts cluster fails and those 5 primaries happen to be part of the failed hosts your VMs will not restart. (One of the primary nodes coordinates the fail-over!) Although the “percentage” option enables you to save additional spare capacity there’s always the chance all primaries fail. 131. How does HA know to restart a VM from a dropped Host? Storage lock will be removed from the metadata 132. How many iSCSI targets will ESX support? 8 for 3.01, (64 for 3.5) 133. How Many Fiber Channel targets (256) (128 on Install) 134. What is Vmotion? (Ability to move running vm from one host to another) 135. What is virtual SMP? When and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling. 136. What version of Linux kernel does ESX run? If they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent 3. 137. Do HA use vmotion?

The answer is no - vm stops and restarts on ESX other host. 138. What is the different when you use viclient connect to VC and directly to ESX server itself. When you connect to VC you manage ESX server via vpxa (Agent on esx server). Vpxa then pass those request to hostd (management service on esx server). When you connect to ESX server directly, you connect to hostd (bypass vpxa). You can extend this to a trobleshoot case, where connect to esx see one thing and connect to VC see another. So the problem is most likely out of sync between hostd and vpxa, "service vmware-vpxa restart" should take care of it. 139. What was the most difficult VMWare related problem/issue you faced in a production environment and what were the specific steps you took to resolve it? HA issues – because of dns problems, the hosts are unable to communicate together. Corrected by adding all servers ip’s in each server’s /etc/hosts file VM was not powered up – because the swap file was locked by another host, when I try to power on the vm its not powering up. After releasing the lock its powered on. 140. When was the last time you called VM Support and what was the issue? Licensing related issues. 141. What was the most performance intensive production app that you supported in VMware and what were the some of the challenges that it posed? In exchange sharepoint demo project, getting lot of VLAN issues. (its my experience, you can say yours) 142. How would you determine that a perf intensive app is a good candidate? Spefically what tools would you use to identify candidates. Specifically inside those tools what metrics would you use?

143. What is your philosophy on how much of the data center can be virtualized? (If the interviewer wants max virtualization, but the interviewee is not convinced that this is a good idea, this could be a deal breaker)

144. What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why? (Just trying to figure out if the candidate is keeping up with this ever changing virtualization market) 145. Briefly describe VST, VGT & EST mode and 802.1Q trunking.

146. What licensing is required for Host Profiles? Available with vSphere Enterprise Plus edition. 147. Can Host Profiles work with ESX/ESXi 3.x hosts? No. Only starting with ESX/ESXi 4.0. 148. Can Host Profiles be used with a cluster running both ESX and ESXi hosts?  

Yes, but remember to use an ESX host and not an ESXi host to create a profile for use. In theory, Host Profiles should work with mixed host clusters, as it translates ESX to ESXi, but be careful as there are enough differences between ESX and ESXi that can lead you to make self-inflicted errors when applying Host Profiles. The easiest method is to create clusters that are homogeneous and maintain two different profiles for these two types of clusters.

149. Can Host Profiles work when using the Cisco Nexus 1000v? No, because Host Profiles was designed with the generic vNetwork Distributed Switch. The Cisco Nexus 1000v switch gives administrators finer-grained control of the networking beyond what Host Profiles can apply. 150. What are host profiles? A set of best practiced configuration rules, which are can be applied to entire cluster or to an individual host. So that all the hosts in sync with each other, this will avoid vmotion, drs and ha problems. 151. Virtual Machines show as invalid or orphaned in vCenter Server. Could not power VM, no swap file, failed to power on VM. In vCenter Server, you may find that you have a virtual machine that has an orphan designation or has become invalid. An orphan virtual machine is one that exists in the vCenter Server database but is no longer present on the ESX host. A virtual machine also shows as orphaned if it exists on a different ESX host than the ESX host expected by vCenter Server. A virtual machine can show up as invalid or orphaned in these situations. To resolve these issues, see the troubleshooting steps provided for each situation: 152. What are the available Storage options for virtual machines ? Raw device mappings, VMFS http://searchvmware.techtarget.com/tip/0,289483,sid179_gci1318776_mem1,00.html 153. Can I add 3 TB HDD to VM?

A single HDD can still only be 2TB minus 512bytes, if carved off a VMFS LUN. If you use a RDM in physical compatibility mode, you can go to 64TB. The limits that apply to VMFS-5 datastores are: 

The maximum virtual disk (VMDK) size is 2 TB minus 512 B.



The maximum virtual-mode RDM size is 2 TB minus 512 B.



Physical-mode RDMs are supported up to 64 TB.

154. What is Raw Device Mapping (RDM)? Raw device mapping (RDM) is an option in the VMware server virtualization environment that enables a storage logical unit number (LUN) to be directly connected to a virtual machine (VM) from the storage area network (SAN). RDM is one of two methods for enabling disk access in a virtual machine. The other method is Virtual Machine File System (VMFS). While VMFS is recommended by VMware for most data center applications, RDM can be used for configurations involving clustering between virtual machines, between physical and virtual machines or where SAN-aware applications are running inside a virtual machine. RDM, which permits the use of existing SAN commands, is generally used to improve performance in I/O-intensive applications. RDM can be configured in either virtual compatibility mode or physical compatibility mode. Virtual mode provides benefits found in VMFS, such as advanced file locking and snapshots. Physical mode provides access to most hardware functions of the storage system that is mapped. 155. What are the differences between Virtual and Physical compatibility modes when mapping the Raw Devices to virtual machines? You can configure RDM in two ways: Virtual compatibility mode—this mode fully virtualizes the mapped device, which appears to the guest operating system as a virtual disk file on a VMFS volume. Virtual mode provides such benefits of VMFS as advanced file locking for data protection and use of snapshots. Physical compatibility mode—this mode provides access to most hardware characteristics of the mapped device. VMkernel passes all SCSI commands to the device, with one exception, thereby exposing all the physical characteristics of the underlying hardware. In this mode, the mapping is done as follows, when we create a mapping, the configuration stored in a file and that file is stored with the vm files in datastore. This file points to the raw device and makes it accessible to the vm. 156. What are RDM Limitations? There are two types of RDMs: virtual compatibility mode RDMs and physical compatibility mode RDMs. Physical mode RDMs, in particular, have some fairly significant limitations:

1. 2. 3. 4. 5.

No VMware snapshots No VCB support, because VCB requires VMware snapshots No cloning VMs that use physical mode RDMs No converting VMs that use physical mode RDMs into templates No migrating VMs with physical mode RDMs if the migration involves copying the disk 6. No VMotion with physical mode RDMs Virtual mode RDMs address some of these issues, allowing raw LUNs to be treated very much like virtual disks and enabling functionality like VMotion, snapshotting, and cloning. Virtual mode RDMs are acceptable in most cases where RDMs are required. For example, virtual mode RDMs can be used in virtual-to-virtual cluster across physical hosts. Note that physical-to-virtual clusters across boxes, though, require physical mode RDMs. While virtual disks will work for the large majority of applications and workloads in a VI environment, the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential compatibility issues or allow applications to run virtualized without any loss of functionality. 157. How to Add an RDM Disk to a Virtual Machine in the vSphere Client? You can store virtual machine data directly on a SAN LUN instead of storing it in a virtual disk file. This ability is useful if you are running applications in your virtual machines that must detect the physical characteristics of the storage device. Mapping a SAN LUN allows you to use existing SAN commands to manage storage for the disk. When you map a LUN to a VMFS volume, vCenter Server creates a Raw Device Mapping (RDM) file that points to the raw LUN. Encapsulating disk information in a file allows vCenter Server to lock the LUN so that only one virtual machine can write to it at a time. For details about RDM, see the vSphere Storage documentation. The RDM file has a .vmdk extension, but the file contains only disk information that describes the mapping to the LUN on the ESXi host. The actual data is stored on the LUN. You can create the RDM as an initial disk for a new virtual machine or add it to an existing virtual machine. When you create the RDM, you specify the LUN to be mapped and the datastore on which to put the RDM. Note You cannot deploy a virtual machine from a template and store its data on a LUN. You can only store its data in a virtual disk file. Procedure  Right Click on VM and go to Edit Setting.  On the Hardware Tab Click Add.

 Select Hard Disk and Click Next.  On the Select the type of disk to use, select Raw Device Mapping and click Next.  From the list of SAN disks or LUNs, select a LUN for your virtual machine to access directly and click Next.  Select a datastore for the LUN mapping file and click Next. You can place the RDM file on the same datastore where your virtual machine configuration file resides, or select a different datastore. Note: To use vMotion for virtual machines with enabled NPIV, make sure that the RDM files of the virtual machines are located on the same datastore. You cannot perform Storage vMotion or vMotion between datastores when NPIV is enabled.  Select a compatibility mode and click Next. Physical: Allows the guest operating system to access the hardware directly. Physical compatibility is useful if you are using SAN-aware applications on the virtual machine. However, a virtual machine with a physical compatibility RDM cannot be cloned, made into a template, or migrated if the migration involves copying the disk. Virtual: Allows the RDM to behave as if it were a virtual disk, so you can use such features as taking a snapshot, cloning, and so on. When you clone the disk or make a template from it, the contents of the LUN are copied into a .vmdk virtual disk file. When you migrate a virtual compatibility mode RDM, you can migrate the mapping file or copy the contents of the LUN into a virtual disk.  Accept the default or select a different virtual device node. In most cases, you can accept the default device node. For a hard disk, a nondefault device node is useful to control the boot order or to have different SCSI controller types. For example, you might want to boot from an LSI Logic controller and share a data disk with another virtual machine using a BusLogic controller with bus sharing turned on.  (Optional) To change the way disks are affected by snapshots, click Independent and select an option. Independent – Persistent: Disks in persistent mode behave like conventional disks on your physical computer. All data written to a disk in persistent mode are written permanently to the disk. Independent – Nonpersistent: Changes to disks in nonpersistent mode are discarded when you power off or reset the virtual machine. With nonpersistent mode, you can restart the virtual machine with a virtual disk in the same state every time. Changes to the disk are written to and read from a redo log file that is deleted when you power off or reset.  Click Next.  Click Finish to save the changes. 158. Scope and Use of Capacity IQ? 159. Name of few third party tools you use?

160. How to calculate Snapshots Size? 161. Process of deleting snapshots? 162. What are CPU and Memory Crunch? 163. How many NICS supported in VM H/W ver. 5? 164. What is the difference in installation process of ESX 3.5 and ESXi 5.0? 165. How many policy we have in multipathing? 166. How to see Block size of Datastore in ESXi and how many types of block we have? 167. Can we deploy ESXi on iSCSI Datastore? 168. Max. Datastore supported in ESX 3.5 and ESXi 5.0? 169. What is Difference between vMotion and Storage vMotion? 170. What is use of vKernel port group? 171. What is Memory Ballooning? 172. What is Transparent page Sharing, (TPS)? 173. How many types’ portions required for installing ESX? 174. What do you understand by block size? 175. Tell me 10 important command of ESXi? 176. What kind of bottlenecks we can have and How to analyze and fix it? 177. What is SRM? 178. Perquisites of vMotion? 179. What type of license required for vMotion? 180. I f we delete manually snapshots, so VM can run or not and if not, so how to fix it? 181. Can we enable Tech support mode using CLI? 182. What is NTP and its use? 183. How to import/export syslog in vCenter? 184. How to create alert and alarm in vCenter? 185. How to create schedule Task in vCenter? 186. Do you have exposure to handle multiple vCenter? 187. How to update patches in ESXi? 188. What is function of VMware Tools? 189. How to bulk update vmware tools? 190. What is network Sniffer? 191. Which created during VM power on and deleted after VM power off? 192. Describe the entire process of creating Gold Images? 193. What do you understand by Gold Images? 194. What will be the entire impact on VM, if we remove Host from vCenter? 195. What is Affinty and Anti-Affinity Rules? 196. Explain the process of creating Datastore Cluster? 197. What error you will get, when you going to disable SDRS? 198. Difference between FT and SRM ? 199. How to config cluster? 200. How to promote or demote the Server in HA config? 201. What is SRM? 202. How to config SRM? 203. Cluster maximum? 204. How to link the vcenter’s? 205. ESXi log files ? 206. VMware services? How to restart the services? 207. How to troubleshoot vmotion?

208. Virtual switch port types? 209. What is VLAN? 210. How to change the root password? 211. Not able to access the server via putty? 212. VMware update manager process? 213. How P2v Works? 214. VMware converter port number? 215. VMware converter requirements? 216. VMware converter steps? 217. What is snapshot? 218. VMware snapshot file extension and initial size? 219. How to config vmsafe? 220. Difference between VI and vpshere client? 221. VMware vcenter services? 222. How to increase the c: drive size? 223. How to increase the datastore size? 224. vmfs version? 225. What is cloning? 226. How to remove the host from the cluster? 227. How to setup HA for a VM? 228. How to troubleshoot PSOD? 229. What is WWN? And WWPN? 230. What is chap authentication? 231. How to discover LUN? 232. How to setup maintance mode? 233. What is resource pool? 234. VMware user and admin rights? 235. Esx and ESXi architecture ? 236. What is service console? 237. What is vmkernel ? 238. How to upgrade the ESX server? 239. Difference between patches and upgrades? 240. What is EVC ? 241. How to export syslog to vmware customer care? 242. What backup mechanism ? 243. VMware backup types?( agents) 244. What is template? 245. Difference between template and clone?

What are the major differences between ESX 3.5 and Vsphere? 2> What is the procedure to upgrade from ESX 3.5 to Vsphere? 3> Will HA and DRS work if Vcenter goes down? 5> What is Vmotion? 6> What are the prerequisites to enable Vmotion? 7> Where do configure Vmotion-- Cluster Level, Host level....?

6> What are port groups? 7> How many default ports are created on installation of ESX 3.5? 6> What is default port number for iSCSI? 8> What are templates? 9> What are differences between convert to template and clone to a template options, for a VM? 10> What could be the maximum host failure in a cluster? 11> what is the difference between Vsphere( VI Client) client and Vcenter ? 12> What are the requirements to install Vcenter? 13> What is minimum hardware configurations to install Vcenter? 14> When you deploy 10 Virtual Machines from a template, and power up all the Virtual Machines simultaneously, will there be a IP conflict? If yes how to resolve this | What if DHCP server is disabled | Are there anything we can do to prevent an ip conflict on deploying Virtual machines? 15> What is Service Console? Why do you need Service Console? 16> Does service console work on Linux OS? 17> What is VMkernel? Is Vmkernel based on Linux ? 18> What are different interfaces available to access an ESX host? 19> When you access an ESX Host through VCenter or VI client, does it contact service console or Vmkernel? 20> Are the changes we make through Vcenter or VI client, on service console or VMkernel? 21> What is difference between accessing an Host VI client and Vcenter? 22> What do you mean be resource pools? explain 23> What is NIC teaming, explain in brief the options it provides? 24> What are different types of Converstions? 25> What do you mean by consolidate backup? 26> What are the disaster recovery options available in Vsphere or ESX 3.5? 27> what is Thin Provisioning? 29> What are the maximum number of extents that can added to a LUN? 30> What is DPM, DRS, VMotion and HA ? 1. Explain the physical topology of Virtual Infrastructure 3 Data Centre ? 2. How do you configure Clusters,Hosts,Resource Pools in VI3 ? 3. What are resource pools & whats the advantage of implementing them ? 4. Explain why Vmware ESX Server is preferred over Virtual Server or Workstation for enterprise implementation ? 5. In what different scenarios or methods can you manage a VI3 ?

6. Explain the difference between access through Virtual Infrastructure Client (vi client), Web access, Service Console access(ssh) ? 7. Explain advantages or features of Vmware Virtual Machine File System (VMFS) ? 8. What are the types of datastores supported in ESX3.0 ? 9. How can you configure these different types of datastores on ESX2.5 ? 10. What is Vmware Consolidate Backup (VCB) ? Explain your work exposure in this area ? 11. How do you configure Vmware Virtual Centre Management Server for HA & DRS ? What are the conditions to be satisfied for this setup ? 12. Explain your work related to below terms : VM Provisioning: Alarms & Even Management: Task Scheduler: Hardware Compatibility List: 13. What SAN or NAS boxes have you configured VMware with ? How did you do that ? 14.What kind of applications or setups you have on you Virtual Machines ? 15. Have you ever faced ESX server crashing and Virtual Centre Server crash? How do

you know the cause of these crashes in these cases ? 1. What is Virtualization? 2. What are the inherent benefits of virtualization? 3. What is a Hypervisor? 4. What is ESX Server? 5. What is Hyper-V? 6. What are a host, guest, and virtual machine? 7. What products are available for Server Virtualization? 8. What products are available for desktop virtualization? 9. What is the difference between ESX Server and VMware Server? 10. What is the difference between Hyper-V and Virtual Server? 11. What is the difference between emulation, native virtualization, and paravirtualization? 12. What are the different types of virtualization? 13. Why do I care that VMware ESX uses the VMFS? 14. How do I backup my virtual guest operating systems?

15. What are VMware VMotion & Storage VMotion (SVMotion)? 16. What is VMware HA? 17. What is VMware VCB? 18. What is Virtual Center? 19. What is System Center Virtual Machine Manager? 20. What is a partition? 21. What are: virtual processor, virtual RAM, virtual NIC, & virtual disk? 22. Why do I need to care about the hardware requirements of VMware ESX and Microsoft Hyper-V? 23. What is a snapshot? 24. What is Quick Migration? 25. Why won’t my virtualization product boot from my OS CD to load my new guest OS? 26. What do I need to know about licensing and Virtualization? 27. What is a P2V conversion? 28. What is VDI? 29. What is SoftGrid? 30. What are the best free virtualization options? 31. What is VM Sprawl? 32. How many virtual machines can you run on one host? 33. What is ThinApp? 34. Why is centralized storage so important for enterprise virtualization products? 35. What are the best online resources for Virtualization knowledge? 36. What are the best training options for learning about Virtualization? 37. What is a VMware VCP & a VCDX? 38. What is a virtual datastore? 39. Why should I try virtualization on my desktop PC? 40. What is the Open Virtual Machine Format? 41. Can I virtualize all my servers or should some servers or applications not be virtualized? 42. What are the drawbacks to virtualization? 43. How do I manage my virtualized servers? 44. How much do virtualization products cost? 45. Will Microsoft overtake VMware as the market virtualization leader? 46. How much money can my company save with Server consolidation using virtualization? 47. What is the difference between a fixed and a dynamic virtual hard disk? 48. Where can I download pre-built virtual machines? 49. What are virtual machine additions and integration components? 50. What are some of the VMware ESX Server add-ons that I should consider? 2. 1. What's the difference between a vSwitch and dsSwitch? 2. Explain the PSA.

3. What is VAAI? 4. What is a SCSI reservation? 5. What is the best practices regarding network setup. etc etc. 1. Explain the physical topology of Virtual Infrastructure 3 Data Centre ? 2. How do you configure Clusters,Hosts,Resource Pools in VI3 ? 3. What are resource pools & whats the advantage of implementing them ? 4. Explain why Vmware ESX Server is preferred over Virtual Server or Workstation for enterprise implementation ? 5. In what different scenarios or methods can you manage a VI3 ? 6. Explain the difference between access through Virtual Infrastructure Client (vi client), Web access, Service Console access(ssh) ? 7. Explain advantages or features of Vmware Virtual Machine File System (VMFS) ? 8. What are the types of datastores supported in ESX3.0 ? 9. How can you configure these different types of datastores on ESX2.5 ? 10. What is Vmware Consolidate Backup (VCB) ? Explain your work exposure in this area ? 11. How do you configure Vmware Virtual Centre Management Server for HA & DRS ? What are the conditions to be satisfied for this setup ? 12. Explain your work related to below terms : VM Provisioning: Alarms & Even Management: Task Scheduler: Hardware Compatibility List: 13. What SAN or NAS boxes have you configured VMware with ? How did you do that ? 14. What kind of applications or setups you have on you Virtual Machines ?

15. Have you ever faced ESX server crashing and Virtual Centre Server crash? How do you know the cause of these crashes in these cases ? How VMWare Kernel different from other kernels?

VMWare kernel is a proprietary kernel that means that it is a registered kernel by VMWare Company and it is not based on any other kernel architecture or any other operating system. VMWare consists of a kernel that requires an operating system to boot it. A service console is being provided when VMWare kernel is booted. What are the features provided by VMWare for easy access?

VMWare provides several features to make it easy for the user to access and maintain it. The features are as follows: • VMWare provides web browser interface • It provides easy to use wizard to configure the settings • It provides tools to easily create hosts and maintain it from one place • It provides easy maintenance of Virtual machines • It provides easy graphics to configure the VMWare settings for security What are the features of VMWare Player?

VMWare player is a stand-alone player that comes with the installation of VMWare also. The features that make it more popular are as follows:

• Creation of virtual machines can be done with easy install options. The creation and installation can be done directly to the system. • VMWare Player can run any virtual machine and it can be used by anyone, anywhere. It allows quick and easy access, to take the advantage of security, portability and flexibility to manage the virtual machines. • VMWare player allows sharing of virtual machines with other computers or users. What are the different components used in VMWare infrastructure?

The different and major components used in VMWare infrastructure is as follows: 1. VMWare infrastructure consists of the lowest layer which acts as a ESX server host. 2. VMWare infrastructure also use the virtual centre server that keep tracks of all the VM related images and manage it from one point. 3. VMWare infrastructure (VI) client: this allows the client to interact with user's applications that are running on VMWare. 4. Web browser is used to access the virtual machines. 5. License server is used to create a server that provides licensing to the applications 6. Database servers are used to maintain a database. What are the benefits of virtualization?

Virtualization is a creation of virtual machines and to manage them from one place. It allows the resources to be shared with large number of network resources. Virtualization is having lots of benefits and they are as follows: 1. It helps in saving lots of cost and allows to easily maintaining it, in less cost. 2. It allows multiple operating systems on one virtualization platform. 3. It removes the dependency of heavy hardware to run the application. 4. It provides consolidating servers that are used for crashing of a server purpose 5. It reduces the amount of space being taken by data centres and company data. What is the purpose of a Hypervisor?

Hypervisor is a program that manages the virtual machine. It also act like virtual machine manager that manages the many virtual machines from one place. It allows multiple operating system to share single hardware host. Each operating system in this consists of its own defined space consisting of space, memory and processor. It is used as a controller program to control host processors and resources. It separates out the layer between many operating systems so that one can't conflict with another one. How ESX server related to VMWare?

ESX server is the enterprise edition of VMWare. It provides server virtualization platform that allows many operating systems to be shared together in a convenient way and consists of a centralized management platform that is also known as virtual centre. ESX server is a virtualization technique that is used to create cloud applications and allows easy development of cloud platforms. It is related to VMWare as it is the upper layer of it. What is the difference between ESX and GSX server?

GSX server acts as type 2 hypervisor that gets installed on the host operating system’s hardware like windows and Linux. VMWare workstation gets mixed up with GSX server to provide it more functionality to run your applications and operating systems. ESX server on the other hand, is type 1 hypervisor that runs its software directly on the system’s hardware and it doesn’t require any operating system prior to its installation. It is level 0 hypervisor and it has its own operating system. What is the use of VMWare workstation?

VMWare workstation is software that allows user to run more than one operating system in there system. It provides virtualization to run different applications on many operating systems at a single time. It saves the current configuration of operating system for the user in the form of virtual machines. VMWare allows user to view there application and work with so many different OS without even switching between the OSs. What are the different types of extensions used by VMWare?

1. .log: is used to keep a log file to maintain a key for VMWare. This file allows user to see the problems encountered during any installation or while using VMWare. 2. .nvram: is used to store the state of the virtual machine in system’s BIOS. 3. .vmdk: is a virtual disk file that is used to store the content of virtual machine. 4. .vmsd: stores the information and metadata of the system’s snapshots. 5. .vmsn: is used to store the snapshot state. It stores both the running state and the time when you have taken it. 6. .vmss: stores the suspended state of a virtual machine. 7. .vmtm: stores the configuration team data.

8. .vmx: store the primary configurations for the new virtual machine. How virtual machine’s concept is different for host and guest systems?

Host system is the system that runs the operating system and over which the virtual platform can be installed. The virtual platform that runs another operating system is called as guest operating system. Host and guest can be connected with each other by using the virtual machines. A host system that runs all together its own operating system is called as virtualization host and the guest operating system will be that, which get installed over that operating system. What are some major differences between VMWare Server and ESX server?

• ESX server is a bare metter virtualation platform that is a physical server whereas, VMWare server needs an operating system to run itself. • ESX server is type 1 hypervisor virtualization platform whereas, VMWare server is a type-2 hypervisor virtualization platform. • ESX server gives better performance then VMWare server, due to less overhead. • ESX server have more features available then VMWare server. • VMWare server is good to be used on small platforms and with less resources but, ESX server requires high specifications.

What is the use of Para-virtualization? Para-virtualization is a virtualization technique that allows similar virtual machines to be created on particular hardware. It allows many operating systems to run on host hardware at the same time. It makes good use of resources like processors, memory and networking. It acts as a virtual machine monitor that has high performance and more efficient. It is used for development, testing and production of the virtual machines. It also good in disaster recovery by moving the guest virtual machine till the hardware is being repaired. Why snapshots are really important in VMWare? Snapshots are images that is been taken at a particular point from the virtual guest operating system. The snapshot consists of the virtual machine configurations, memory and the devices that were present at the time of the snapshot. By doing this, you can return back to virtual machine which might have become corrupted or might not be working. Snapshots can be taken anytime according to your need and requirement. Snapshots can be saved and then system can be reverted back in case of any disaster happened to your operating system. What are the disadvantages associated with VMWare virtualization platform? The disadvantage of VMWare virtualization platform is as follows: • VMWare concept requires the knowledge of the concept. • It requires money to buy the resources required for virtualization platform. • It requires high end server with lots of high end configuration and specification that increases the cost. • It requires different technologies that have to be implemented for the enterprise virtualization systems. • Reliability decreases and cost increases in case of the system failures.

1. Difference between ESX3.X and ESX 4 3. How to access the ESX and ESXi? 4. ESXi server ports?, ssh, VUM, vmotion, SCSI,HA 75. how to config VCB( vmware consolidated backup)- port?- how it works? 76. how to install new VM – step by step ? 1. Explain about your production environment? How many cluster’s, ESX, Data Centers, H/w etc ? 2. How does VMotion works? What’s the port number used for it? There are 3 underlying action happening in vMotion. First:-

The entire state of a virtual machine is encapsulated by a set of files stored on shared storage such as Fibre Channel or iSCSI Storage Area Network (SAN) or Network Attached,Storage (NAS). VMware vStorage VMFS allows multiple ESX® to access the same virtual machine files concurrently. Second:The active memory and precise execution state of the virtual machine is rapidly transferred over a high speed network, allowing the virtual machine to instantaneously switch from running on the source ESX host to the destination ESX host. VMotion keeps the transfer period imperceptible to users by keeping track of on-going memory transactions in a bitmap. Once the entire memory and system state has been copied over to the target ESX host, VMotion suspends the source virtual machine, copies the bitmap to the target ESX host, and resumes the virtual machine on the target ESX host. This entire process takes less than two seconds on a Gigabit Ethernet network. Third:The networks being used by the virtual machine are also virtualized by the underlying ESX host, ensuring that even after the migration, the virtual machine network identity and network connections are preserved. VMotion manages the virtual MAC address as part of the process. Once the destination machine is activated, VMotion pings the network router to ensure that it is aware of the new physical location of the virtual MAC address. Since the migration of a virtual machine with VMotion preserves the precise execution state, the network identity, and the active network connections, the result is zero downtime and no disruption to users. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Prerequisites for VMotion How does HA works? Port number? How many host failure allowed and why? What are active host / primary host in HA? Explain it? Prerequisites for HA ? How do DRS works? Which technology used? What are the priority counts to migrate the VM’s? How does snap shot’s works? What are the files will be created while creating a VM and after powering on the VM? If the VMDK header file corrupt what will happen? How do you troubleshoot? Prerequisites VC, Update manager? Have you ever patched the ESX host? What are the steps involved in that?

13. Have you ever installed an ESX host? What are the pre and post conversion steps involved in that? What would be the portions listed? What would be the max size of it? 14. I turned on Maintenance mode in an ESX host, all the VM’s has been migrated to another host, but only one VM failed to migrate? What are the possible reasons? 15. How will you turn start / stop a VM through command prompt? 16. I have upgraded a VM from 4 to 8 GB RAM; it’s getting failed at 90% of powering on? How do you troubleshoot? 17. Storage team provided the new LUN ID to you? How will you configure the LUN in VC? What would be the block size (say for 500 GB volume size)? 18. I want to add a new VLAN to the production network? What are the steps involved in that? And how do you enable it? 19. Explain about VCB? What it the minimum priority (*) to consolidate a machine? 20. How VDR works? 21. What’s the difference between Top and ESXTOP command? 22. How will you check the network bandwidth utilization in an ESXS host through command prompt? 23. How will you generate a report for list of ESX, VM’s, RAM and CPU used in your Vsphere environment? 24. What the difference between connecting the ESX host through VC and Vsphere? What are the services involved in that? What are the port numbers’s used? 25. How does FT works? Prerequisites? Port used? 26. Can I VMotion between 2 different data centers? Why? 27. Can I deploy a VM by template in different data centers ? 28. I want to increase the system partition size (windows 2003 server- Guest OS) of a VM? How will you do it without any interruption to the end user? 29. Which port number used while 2 ESX transfer the data in between? 30. Unable to connect to a VC through Vsphere client? What could be the reason? How do you troubleshoot? 31. Have you ever upgraded the ESX 3.5 to 4.0? How did you do it? 32. What are the Vsphere 4.0, VC 4.0, ESX 4.0, VM 7.0 special features? 33. What is AAM? Where is it used? How do you start or stop through command prompt? 34. Have you ever called VMWare support? Etc 35. Explain about Vsphere Licensing? License server? 36. How will you change the service console IP? 37. What’s the difference between ESX 3.5 and ESX 4.0?