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VMWare Interview Questions

1.What is VMWare Esx Server?

 VMware ESXi is the industry-leading, purpose-built bare-metal hypervisor. ESXi installs directly    onto  your physical server enabling it to be partitioned into multiple logical servers referred to as virtual machines. Customers can use ESXi for free with vSphere Hypervisor or as part of a paid vSphere edition.

2.What are Version available in ESX Server? Which version do you handle in your organization?

We are using ESXi 5, 5.1 and 5.5 in our organization

3. 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

4.How to set the time delay or Force to BIOS screen for a Virtual Machine?
Go to VM settings, choose options tab and select boot option, set the delay how much you want.

5. What is a template?
Template is exact copy of VM from which we can convert a VM into Template, and it can be deployed to multiple VM’s and it cannot be powered on once it’s changed to template. This is used to quick provisioning of VM’s.

6. What to do customize the windows virtual machine clone?
Run sysprep on the particular VM.

7. What are the common issues with snapshots?
If you configure the VM with Mapped LUN’s as physical, you need to remove it to take a snapshot.

8.What happens if ESX host is taken to maintenance mode?
If Using Single ESXi setup, all VMs need to be shut down before getting into maintenance mode. If using vCenter setup If DRS is enabled, the VMs will be migrated to other hosts automatically or need to use VMotion to migrate the VM to another host.

9.What are the steps needed to consideration when we initiate a snapshot?
Virtual Machine Configuration, State of the Virtual Machine Hard Disk file, State of the Virtual Machine Memory.

10.While planning to upgrade vCenter, you found the old vCenter is running on Windows Server 2003. What Windows Operating System is required for vCenter 5.x?
Windows 2008 SP2 or Later

11.You’re creating a list of ports you need the network admin to open on the firewall. What is port is used for on vCenter?
Port 902

12. Consider if vMotion is not working. Explain all the possible reason?

  1. Ensure vMotion is enabled on all ESX/ESXi hosts
  2. Verify that time is synchronized across environment
  3. Verify that the required disk space is available
  4. Ensure that all VMware pre requisites are met

    What VMware functionality requires an IP address for sure?

Service Console and VMKernel (VMotion and iSCSI)


  • Explain the requirements for converting physical machine to VM?
    1. One New ESX Server is need to import Machine
    2. VI Convertor tools is required
    3. Agent should be present in the physical machine.


  • What is VMWare consolidated backup?
    It is a backup framework, which supports 3rd party utilities to take backups of ESX servers and Virtual Machines.


  • What is a .vmdk file?

This isn’t the file containing the raw data. Instead it is the disk descriptor file which describes the size and geometry of the virtual disk file. This file is in text format and contains the name of the –flat.vmdk file for which it is associated with and also the hard drive adapter type, drive sectors, heads and cylinders, etc.


  • What is the difference between clone and template in VMware?
    See in the Posts


  • What is a snapshot?

A snapshot is a “point in time image” of a virtual guest operating system (VM). That snapshot contains an image of the VMs disk, RAM, and devices at the time the snapshot was taken. With the snapshot, you can return the VM to that point in time, whenever you choose. You can take snapshots of your VMs, no matter what guest OS you have and the snapshot functionality can be used for features like performing image level backups of the VMs without ever shutting them down.


  • What is the difference between VMware HA and vMotion?

VMware HA is used in the event when any of the hosts inside a cluster fails then all the virtual machines running under it are restarted on different host in the same cluster. Now HA is dependent on vMotion to perform live migration of the vms to different host so vMotion is just used for the migration purpose between multiple hosts which is also used by other functionality like DRS.

  • What is storage vMotion?

See the post


  • What is VMware DRS and how does it works?

See the post


  • What is VMware Fault Tolerance?
    See the post


  • In a cluster with more than 3 hosts, can you tell Fault Tolerance where to put the Fault Tolerance virtual machine or does it chose on its own?

You can place the original (or Primary virtual machine). You have full control with DRS or vMotion to assign it to any node. The placement of the Secondary, when created, is automatic based on the available hosts. But when the Secondary is created and placed, you can vMotion it to the preferred host.


  • How many virtual CPUs can I use on a Fault Tolerant virtual machine?

vCenter Server 4.x and vCenter Server 5.x support 1 virtual CPU per protected virtual machine.


  • What happens if vCenter Server is offline when a failover event occurs?

When Fault Tolerance is configured for a virtual machine, vCenter Server need not be online for FT to work. Even if vCenter Server is offline, failover still occurs from the Primary to the Secondary virtual machine. Additionally, the spawning of a new Secondary virtual machine also occurs without vCenter Server.


  • What are the monitoring methods used for vSphere HA?
    The Master and Slave hosts uses two types of monitoring the status of the hosts
  • Datastore Heartbeat
  • Network Heartbeat
  • What is the use of vmware tools?
    VMware Tools is a suite of utilities that enhances the performance of the virtual machine’s guest operating system and improves management of the virtual machine. Without VMware Tools installed in your guest operating system, guest performance lacks important functionality. Installing VMware Tools eliminates or improves these issues:
  • Low video resolution
  • Inadequate color depth
  • Incorrect display of network speed
  • Restricted movement of the mouse
  • Inability to copy and paste and drag-and-drop files
  • Missing sound
  • Provides the ability to take quiesced snapshots of the guest OS
  • Synchronizes the time in the guest operating system with the time on the host
  • Provides support for guest-bound calls created with the VMware VIX API
  • When is a swap file created ?

When the guest OS is first installed in the VM

  • What is the Maximum number of LUNs that can be attached to a host (ESXi 5.0)


  • What is the Maximum number of vCPUs that can be assigned to a VM ?(ESXi 5.0)



  • What happens to the VMs if a standalone host is taken to maintenance mode?
    • In case of standalone servers , VMware recommends that VMs should be powered off before putting the server in maintenance mode
    • If we put the standalone host in maintenance mode without powering off the VMs, it will remain in the ‘entering maintenance mode’ state until the VMs are all shutdown
    • When all the VMs are powered down, the host status changes to ‘under maintenance’
  • What is vSAN?
    It is a hypervisor-converged storage solution built by aggregating the local storage attached to the ESXi hosts managed by a vCenter.


  • Post conversion steps in P2V
  • Adjust the virtual hardware settings as required
  • Remove non present device drivers
  • Remove all unnecessary devices such as serial ports, USB controllers, floppy drives etc..
  • Install VMware tools
  • Which is the command used in ESXi to manage and retrieve information from virtual machines?


  • Which is the command used in ESXi to view live performance data?


  • What is the Command line tool used in ESXi to manage virtual disk files? Vmkfstools


  • What is port number used for vMotion ?


  • Can you map a single virtual switch to multiple physical NICs? This method is called NIC teaming.


  • VMKernel portgroup can be used for:
  • vMotion
  • Fault Tolerance Logging
  • Management traffic

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