VMware and Windows Interview Questions: Part 1

VMware & Windows Interview Questions : Part 1

  1. Windows 2003 vs Windows 2008

    • RODC
    • WDS instead of RIS
    • Services have been changed as roles - server manager
    • Introduction of hyper V- only on 64 bit versions
    • Enhanced event viewer
    • Bitlocker feature
    • Server core installation without GUI
    • MMC 3.0, with three pane view
    • Key management services(KMS) to activate Windows OS without connecting to Microsoft site
    • Performance enhancement using technologies like Windows SuperFetch,ReadyBoost and Readydrive
    • Windows Aero user interface
    • Instant search
    • Support for IPv6 in DNS

  1. ESX vs ESXi

    • ESXi has no service console which is a modified version of RHEL
    • ESXi is extremely thin hence results in fast installation + fast boot
    • ESXi can be purchased as an embedded hypervisor on hardware
    • ESXi has builtin server health status check

  1. ESXi 4.1 vs ESXi 5.0 - Migration

    • Local upgrade from CD
    • VMware update manager (only supports upgrade of ESX/ESXi 4.x to ESXi 5.0)

  1. ESXi 4.1 vs ESXi 5.0 - Features

    • vSphere Auto deploy
    • Storage DRS
    • HA - Primary/secondary concept changed to master/slave
    • Profile driven storage
    • VMFS version - 3 → 5
    • ESXi firewall
    • VMware hardware version - 7 →  8
    • VMware tools version - 4.1 → 5
    • vCPU - 8 → 32
    • vRAM - 256 → 1 TB
    • VMs per host - 320 → 512
    • RAM per host - 1TB → 2TB
    • USB 3.0 support
    • vApp

    • Schema Master
    • Domain naming master
    • Infrastructure master
    • PDC Emulator
    • RID master

    • GPO
    • Templates (ADMX)
    • Block inheritance
    • Enforced
    • Loopback policy

  1. Forest and Domain concepts

  1. OSI layer

    • Application Layer
    • Presentation Layer
    • Sessions Layer
    • Transport Layer
    • Network Layer
    • DataLink layer
    • Physical Layer

  1. ASA - site to site VPN

    • Uses an agent called FDM - Fault domain manager
    • HA now talks directly to hostd instead of using vcenter agent vpxa
    • Master/slave concept
    • Master
      • monitors availability of hosts/VMs
      • manages VM restarts after host failure
      • maintains list of all VMs in each host
      • restarting failed VMs
      • exchanging state with vcenter
      • monitor state of slaves
    • Slave
      • monitor running VMs and send status to master and performs restart on request from master
      • monitors master node health
      • if master fails, participates in election
    • Two different heartbeat mechanisms - Network heartbeat and datastore heartbeat
    • Network heartbeat
      • Sends between slave and master per second
      • When slave is not receiving heartbeat from master, checks whether it is isolated or master is isolated or has failed
    • Datastore heartbeat
      • To distinct between isolation and failure
      • Uses ‘Power On’ file in datastore to determine isolation
      • This mechanism is used only when master loses network connectivity with hosts
      • 2 datastores are chosen for this purpose

    • Isolation response
      • PowerOff
      • Leave Powered On
      • Shutdown

    • vMotion enables live migration of running virtual machines from one host to another with zero downtime
    • Prerequisites
      1. Host must be licensed for vMotion
      2. Configure host with at least one vMotion n/w interface (vmkernel port group)
      3. Shared storage (this has been compromised in 5.1)
      4. Same VLAN and VLAN label
      5. GigaBit ethernet network required between hosts
      6. Processor compatibility between hosts
      7. vMotion does not support migration of applications clustered using Microsoft clustering service
      8. No CD ROM attached
      9. No affinity is enabled
      10. vmware tools should be installed

  1. RAID
    • Redundant Array of Independent disks
    • A category of disk drives that uses 2 or more drives in a combination for redundancy and performance
    • Most common RAIDs: RAID 0(Striped), RAID 1(Mirroring), RAID 5

  1. Backup types
    • Backup types
      1. Full backup - Will take the backup of all selected files and reset the archive bit
      2. Copy backup - Will take the backup of all selected files but does not reset the archive bit
      3. Incremental backup - Will take the backup of files whose archive bits are set and resets it after backup
      4. Differential backup - Will take the backup of files whose archive bits are set but does not reset it after backup

  1. 2003 → 2008 migration
    • Can be done only by logging in to Windows 2003 server
    • Min of Windows 2003 SP1 required
    • Can be migrated only to same version, except for Windows server 2003 standard which can be migrated to either standard or enterprise
    • Extra space of 30 GB required prior migration
    • Cannot upgrade to server core
    • Perform forestprep and domainprep to 2008 using 2008 cd before migrating. (Copy sources/adprep folder for this)

  1. ESXi update manager

    • Global catalog (GC) is a role handled by domain controllers in an Active directory model.
    • The global catalog stores a full copy of all objects in the directory for its host domain and a partial copy of all objects for all other domains in the forest.
    • ‘Partial copy’ refers to the set of attributes that are most used for searching every object in every domain.
    • All domain controllers can be promoted as a GC.
    • GC helps in faster search of AD objects.  
    • The replicas that are replicated to the global catalog also include the access permissions for each object and attribute.
    • If you are searching for an object that you do not have permission to access, you do not see the object in the list of search results. Users can find only objects to which they are allowed access.
    • Global catalog server clients depend on DNS to provide the IP address of global catalog servers. DNS is required to advertise global catalog servers for domain controller location.
    • By default, first DC of in a forest will be a global catalog server

  1. Basic networking concepts

  1. RODC
    • New feature in Windows 2008
    • Only have the read only copy of directory database
    • RODC will have all the objects of a normal DC in read only mode. But this doesn’t include passwords. RODC does not store password of accounts.
    • Updates are replicated to RODC by writable DC
    • Password caching : A feature which enables RODC to cache password of the logged in users.
    • Password Replication Policy: Determines whether the password can be cached or not.
    • DNS can be integrated with RODC but will not directly register client updates. For any DNS change, the RODC refers the client to DNS server that hosts a primary or AD integrated zone

  1. NAS vs SAN
    • Both used as storage solution
    • NAS can be used by any device connected using LAN whereas SAN is used only by server class devices with SCSI
    • NAS is file based whereas SAN is block based storage
    • NAS is cheap while SAN is expensive
    • SAN is comparatively faster than NAS

    • Distributed Resource Scheduler
    • It is a feature of a cluster
    • DRS continuously monitors utilization across the hosts and moves virtual machines to balance the computing capacity
    • DRS uses vMotion for its functioning
    • Types of DRS
      1. Fully automated - The VMs are moved across the hosts automatically. No admin intervention required.
      2. Partially automated - The VMs are moved across the hosts automatically during the time of VM bootup. But once up, vCenter will provide DRS recommendations to admin and has to perform it manually.
      3. Manual - Admin has to act according to the DRS recommendations

    • Shared storage
    • Processor compatibility of hosts in the DRS cluster
    • vMotion prerequisites

    • Ensure vMotion is enabled on all ESX/ESXi hosts
    • Ensure that all vmware pre requisites are met
    • Verify if the ESXi/ESX host can be reconnected or if reconnecting the ESX/ESXi host resolves the issue
    • Verify that time is synchronized across environment
    • Verify that the required disk space is available

  1. What happens if a host is taken to maintenance mode
    • Hosts are taken to maintenance mode during the course of maintenance
    • In a single ESX/ESXi setup, all the VMs need to be shutdown before getting into maintenance mode
    • In a vCenter setup If DRS is enabled, the VMs will be migrated to other hosts automatically.
    • Using vmkftools
    • Copy the vmdk file and attach to a new VM
    • Using VMware converter

  1. Explain traverse folder
    • Allows or denies moving through a restricted folder to reach files and folders beneath the restricted folder in the folder hierarchy.
    • Traverse folder takes effect only when the group or user is not granted the "Bypass traverse checking user" right in the Group Policy snap-in. This permission does not automatically allow running program files.


  1. excellent very usefull...thank you dude

  2. Thanks for your feedback Satish...

  3. Thanks bro!, pls update frequently

  4. Simply superb... Very helpful..

  5. Very Informative!!! Thanks a ton!!!

  6. Thanks a lot really helped me

  7. thanks a lot really helped me

  8. Thank you very much. Can you please share active directory scenario based question.

  9. good basic KB

  10. thank you so much for your information .....

  11. I hope you will keep writing on this topic.

  12. Very useful... Proud to be a friend of Nithin... Keep marching Bro....!!!

  13. All questions and their relevant answers are quite helpfull.

    Thanking you.

  14. A differential backup is a cumulative backup of all changes made since the last full or normal backup, i.e., the differences since the last full backup

  15. this is very helpfull........

  16. great maximum admin task or related question covered

  17. Thank you for sharing, this is a good start for interview preparation.


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