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  • Recommended Hyper-V config

    Hi all,

    i'd really appreciate expert advice on this as my current support provider don't seem to be coming up with the answers.

    Scenario:

    2 x HP Proliant ML370/G6 servers (S1 and S2) - each have 4 physical nics
    All hosts and guests run WS2008 R2.

    S1 = 32Gb ram, 2 x E5520 cpus, 1.8Tb raid 5 sas 10k disks (bios and drivers up-to-date)

    Hyper-v Guests:
    VDC (4Gb static, 2 vpus) - domain controller
    VPS (4Gb static, 2 vcpus) - print server

    S2 = 68Gb ram, 2 x E5620 cpus, 2.8Tb raid 5 sas 10k disks (bios and drivers up-to-date)

    Hyper-v guests:
    VTS - 25Gb static, 4 vcpus - currently DYNAMIC disk (RDS (terminal server)
    EXCHANGE - 20Gb static, 4 vcpus - currently DYNAMIC disk (Exchange 2007 spe, ru6)
    VIRTUE 8Gb static, 2 vpcus - currently DYNAMIC disk (DMS)
    VWSUS - 4Gb static, 2 vcpus - currently DNAMIC disk (MS updates)

    As each ML370 host has 4 physical nics, i've created a virtual lan for each (VL2, VL3, VL4)

    On S2 only VIRTUE and VWSUS share one of these (as they are not as important as VTS and EXCHANGE).

    The problem is that VTS users (RDS) experience screen freezes and sluggishness when working. Screen freezes often happen when accessing outlook 2010. When i check EXCHANGE the disk I/O is very high.
    No one seems to know why.

    Things i'm planning on doing:
    Convert VTS and EXCHANGE from 'dynamic' to 'fixed' disks. The other two can stay as dynamic, unless suggested otherwise.

    Now, currently ALL VL nics have "allow managment operating system to share this network adapter" ticked. Not sure whether it should be this way or not.

    The host os uses its own physical nic.

    So, does this sound like a reasonable setup, or are their obvious flaws in the config of these two host machines AND the guests on them.

    We have 2 physical and 1 virtual DC/GC and replication across all 3 often fails, not sure if this makes a diff to the rest of the stuff above.

    I know this is a long read, but i could really do with the help. It's also a decent learning curve for me if i can integrate any advice you guys have to offer.

    Many thanks in advance.

  • #2
    Re: Recommended Hyper-V config

    There are a few recommendations.

    1. You should team your VM NICs and enable VMQ if possible and then have them all use the same vswitch
    2. Do not share the VM NICs with the host OS.
    3. Separate you OS from your data by using two VHDs. The OS always needs to be on the IDE controller, all other VHD's should be on the SCSI controller which gives better performance
    4. Make you disks fixed unless no data is changing. Every time a dynamic disk grows it first overwrites the space it's claiming with blank data and then writes the actual data.
    Regards,
    Jeremy

    Network Consultant/Engineer
    Baltimore - Washington area and beyond
    www.gma-cpa.com

    Comment


    • #3
      Re: Recommended Hyper-V config

      Originally posted by JeremyW View Post
      There are a few recommendations.

      1. You should team your VM NICs and enable VMQ if possible and then have them all use the same vswitch
      I was advised against this by my support team. I think they were originally teamed, but that was way before any issues arrived, so right now i can't really 'claim' that unteaming them has caused issues. What is VMQ?

      2. Do not share the VM NICs with the host OS.
      I will untick that box. Does it add a real overhead to the traffic on the nic then?

      3. Separate you OS from your data by using two VHDs. The OS always needs to be on the IDE controller, all other VHD's should be on the SCSI controller which gives better performance
      Hmmm....ok. So on exchange, i move the mailstore to another VHD? Currently, in an attempt to alleviate the issues, we created a new VHD and moved the transaction logs to it. It 'seemed' to help a little, but not much.

      4. Make you disks fixed unless no data is changing. Every time a dynamic disk grows it first overwrites the space it's claiming with blank data and then writes the actual data.
      Yes, i'll be doing this overnight.

      Many thanks for your input. Again i'd appreciate advice on my replies.

      Comment


      • #4
        Re: Recommended Hyper-V config

        Originally posted by k.jacko View Post
        I was advised against this by my support team. I think they were originally teamed, but that was way before any issues arrived, so right now i can't really 'claim' that unteaming them has caused issues. What is VMQ?
        VMQ is Virtual Machine Queue. http://en.wikipedia.org/wiki/VMQ
        This needs to be supported by the NICs and the teaming software so you'll need to check on that.
        Teaming the NICs for Hyper-V is supported and if the NICs support VMQ then it's recommended.

        Originally posted by k.jacko View Post
        I will untick that box. Does it add a real overhead to the traffic on the nic then?
        Potentially but your issues are probably due to your disk configuration.
        Originally posted by k.jacko View Post
        Hmmm....ok. So on exchange, i move the mailstore to another VHD? Currently, in an attempt to alleviate the issues, we created a new VHD and moved the transaction logs to it. It 'seemed' to help a little, but not much.
        You need to get all your data off the OS drive and on to a VHD connected to the virtual SCSI controller.

        Changing to fixed size VHD and moving your data to new VHDs on the virtual SCSI controller should help a lot.

        Are you using snapshots in Hyper-V Manager? If so, you need to stop. Delete all snapshots and shutdown the VMs. You should see the status change to "Merging" Once they're finished merging you can boot them up again.

        Using snapshots will cause performance issues. Snapshots are only indented for lab environments.
        Regards,
        Jeremy

        Network Consultant/Engineer
        Baltimore - Washington area and beyond
        www.gma-cpa.com

        Comment


        • #5
          Re: Recommended Hyper-V config

          Originally posted by JeremyW View Post
          VMQ is Virtual Machine Queue. http://en.wikipedia.org/wiki/VMQ
          This needs to be supported by the NICs and the teaming software so you'll need to check on that.
          Teaming the NICs for Hyper-V is supported and if the NICs support VMQ then it's recommended.
          Got some reading to do then i guess.


          You need to get all your data off the OS drive and on to a VHD connected to the virtual SCSI controller.
          I'm a little unsure as what is deemed 'data' on an Exchange server 2007 setup. Sorry for sounding dim.

          Changing to fixed size VHD and moving your data to new VHDs on the virtual SCSI controller should help a lot.
          Cool. Will have a go at this.

          Are you using snapshots in Hyper-V Manager? If so, you need to stop. Delete all snapshots and shutdown the VMs. You should see the status change to "Merging" Once they're finished merging you can boot them up again.

          Using snapshots will cause performance issues. Snapshots are only indented for lab environments.
          I'm not using snapshots as our BDR covers our servers sufficiently.
          I merged the differencing disks last night.
          But i guess i need to convert to fixed disk and move data to a new (scsii) vhd
          before i'll see any increase in performance?
          Attached Files
          Last edited by k.jacko; 23rd March 2012, 14:34.

          Comment


          • #6
            Re: Recommended Hyper-V config

            Originally posted by k.jacko View Post
            I'm a little unsure as what is deemed 'data' on an Exchange server 2007 setup. Sorry for sounding dim.
            No problem. Data would basically be any databases, like SQL or Exchange's db, or file shares. Anything that contains information that is unique, that you couldn't just rebuild something to get the information back.
            Regards,
            Jeremy

            Network Consultant/Engineer
            Baltimore - Washington area and beyond
            www.gma-cpa.com

            Comment

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