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Standalone Hyper-V Host? RRS feed

  • General discussion

  • I have read that DPM 2012 offers faster backups of VMs on a standalone Hyper-V host then DPM 2010.

    What is meant by "standalone" Hyper-V host?

    If we have a Windows 2008 R2 Datacentre server (full install not core) hosting several VMs on local storage (with no redundancy or resiliance), is this a standadlone Hyper-V host?

    Bruce.

    Thursday, April 5, 2012 8:37 PM

All replies

  • HI,

    Correct, we mean it is not a clustered Hyper-V server.  You should see much faster guest backups because we now track .vhd file changes at the block level and can bring those changed blocks over without having to do block by block compare like we use to do, or still have to do on Windows 2008 clustered hyper-V servers.  


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.

    Friday, April 6, 2012 5:01 AM
    Moderator
  • I think I understandwhat you're saying...

    At the moment every block in the latest backup of the VHD on DPM is compared with the VHD on the protected Hyper-V server, and any blocks that have changed are transferred to DPM to form a new snapshot.

    But with DPM2012 either the Hyper-V server or DPM will have tracked what blocks have changed since the last backup and will only transfer those blocks?

    In the former scenario, would I be correct in assuming that DPM checks for changed blocks by getting the protected server to create a hash of each block, then comparing this with a hash of the same block on the protected server to determine if it had changed?

    I.e. this avoids the requirement for DPM2010 to transfer each block from the protected server to DPM for comparson (thus creating huge load on the network, which I haven't observed)?

    This tallys with my observation of VM backups, where DPM reports that with a VM Express full backuo only a few MB/GB is transferred to DPM (maybe around 5% of the size of the VHD), but it seems to take considerably longer to do this than it would take if it were simply transfering that amount of data?

    For my backups the VMs are backed up each night and the time taken is acceptable (finishes by 3am). But with the more efficient way DPM2012 backs-up VMs, might there be be potential to do Express Full backups/snapshots during the day as well?

    Regards,

    Bruce.

    Friday, April 6, 2012 6:26 PM
  • Hi Bruce,

    You are correct in all counts, except the hash blocks sent between the PS and DPM is not that great.  In fact, if you place a VM into a saved state, then perform 2 backup to back backups, the amount of data transfered will be identical and is strictly the hash blocks since obviously no changes were done in the saved .vhds.

    If you have secondary protection setup on DPM 2010,  for Hyper-V workloads we do track block level changes on the primary DPM Server, so you can see the huge benefit because the backups are much much quicker on a secondary DPM server versus the primary dpm server.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.

    Friday, April 6, 2012 7:21 PM
    Moderator