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Do you Backup your VMs Serially (EVEN when using Hardware VSS Providers)??? RRS feed

  • Question

  • My Environment: Hyper-V R2 4 node cluster with CSV connected to PS4000XV Equallogic SAN. All hosts have latest hardware VSS provider installed. DPM 2010 is configured to backup the Hyper-V environment.

    My question is do you still backup your VMs serially even when using hardware VSS providers?
    How many VMs do you have per protection group?

    I am having big problems with backing up my CSV VMs with DPM 2010. First I had all VMs in the same protection group (approx 20 VMs) and the maxparallelbackups registry setting was set to 3 (the default setting). I found that sometimes overnight when the backups started my VMs stopped randomly. Looking at the logs it would seem that the cluster hosts lose connectivity to the CSV when the backups start (Event ID: 5120 and 5121). It would seem that there was too much contention for the CSV volume during the backups (the CSV volume is moved to a new co-ordinator and then goes into redirected mode continuously while hardware snapshots are created for each VM).

    I changed the registry setting for maxparallelbackups from 3 to 1 hoping this would resolve it but the problem still occurs.
    Having logged a call with MS they have asked me to re-configure the protection groups so that there are no more than 4 VMs per protection group and stagger the backups that way. I am not convinced that this will resolve the issue (but make it less likely to happen) as each protection group as it stands will still be able to run a maximum of 4 VM backups in parallel should each VM happen to be located on a different host at the time.

    Do you use serial backups even when using the hardware VSS provider to backup VMs?
    I am keen to hear from anyone that is protecting a large number of VMs on a CSV with DPM 2010 with decent performance and reliability and how you have DPM backups configured?

    If I can get backups stable with decent performance I will migrate more VMs onto the cluster.


    Microsoft Partner
    Tuesday, April 19, 2011 8:44 PM

Answers

  • Closing this thread due to inactivity. If you still need help in resolving this thread then please re-open it
    Cheers, Tyler F [MSFT] - This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, May 20, 2011 7:24 PM
    Moderator

All replies

  • Having similar issues myself.  I have tried both serialized and not serialized for hardware backups with the same problem either way.  The recommendation of 4 VMs per protection group seems a bit excessive.  I have 110 VMs on this particular cluster.  To protect that many VMs DPM would be very cumbersome.  According to Microsoft you are supposed to be able to support more.

    Migrating from the System VSS Provider to a Hardware VSS Provider

    http://technet.microsoft.com/en-us/library/ff634216.aspx

     

    If you have a chance send me your case number the the mail link on my site.  I will pass mine back to you.  Maybe we can work this from 2 angles.

     

    Rob McShinsky (http://www.VirtuallyAware.com)


    http://www.VirtuallyAware.com
    Wednesday, April 20, 2011 7:24 PM
  • Closing this thread due to inactivity. If you still need help in resolving this thread then please re-open it
    Cheers, Tyler F [MSFT] - This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, May 20, 2011 7:24 PM
    Moderator