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Cluster Shared Volume VSS

    Question

  • I'm having an issue with VSS on my clustered storage.

    We run a Nimble cluster, backed up by Veeam. For each VM, there is a separate volume created on Nimble. I use iSCSI to attach this to the cluster and mount it as a CSV. Inside this volume I create a VHD and attach that to the VM. (This may seem unnecessary, but connecting the volume straight to the VM as an iSCSI drive prevents Veeam from backing up that drive)

    Everything works fine, except VSS fails on this data volume. In my test environment, I've created a volume twice the size of the VHD (just to make sure there aren't any lurking space issues causing a failure). 

    vssadmin is of little help. If I list volumes, only the system volume, c: and d: show up - none of the volumes located in C:\ClusterStorage do. But I am certain that it should work. Inside the cluster storage we have \HV-Cached\ and \HV-Uncached\ volumes, both of which cause no problems with VSS.

    In FCM, there is not a Shadowcopies tab when I look at the properties of a CSV (This is including the volumes that work properly). 

    When I attempt a backup, I get 3 errors. First is this one, which pops twice:

    The flush and hold writes operation on volume  timed out while waiting for a release writes command.

    Source: volsnap

    Event ID: 8

    Level: Error

    User: N/A

    The second:

    Software snapshot creation on Cluster Shared Volume(s) ('\\?\Volume{7676a6a8-aa4a-4021-812a-0bec9a51469d}\') with snapshot set id '51507b5a-a22f-421d-84b9-94e7f18084ad' failed with error 'HrError(0x80042308)(2147754760)'. Please check the state of the CSV resources and the system events of the resource owner nodes.

    Source: FailoverClustering

    Event ID: 5217

    Level: Error

    User: SYSTEM


    This is purely a test VM with absolutely no activity going on at the time of the snapshots.

    I should add that I have set all volumes to use the Microsoft Software VSS provider - not the Nimble VSS provider. (That causes a whole host of other problems, I had to disable that long ago to get any sort of app aware processing to work)

    Unfortunately I have limited experience dealing with VSS, so I'm not sure what information I can give that would be helpful - but am happy to provide and even more happy for any help!

    Friday, April 21, 2017 10:17 PM

All replies

  • Hi Sir,

    >> Inside the cluster storage we have \HV-Cached\ and \HV-Uncached\ volumes, both of which cause no problems with VSS.

    >>Inside this volume I create a VHD and attach that to the VM.

    >>Everything works fine, except VSS fails on this data volume.

    That VM has more than one disks , one of them is stored on that new CSV ?

    Without that New VHD , that VM can be backed up successfully ?

    All of the CSV disks are created from same iSCSI target "Nimble" ?

     

    Best Regards,

    Elton


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    Monday, April 24, 2017 9:22 AM
    Moderator
  • Yes that is all correct.

    For clarity, I've reproduced the problem on a couple test environments, so it's not isolated to that individual data volume.

    Monday, April 24, 2017 9:13 PM
  • Hi Sir,

    A backup application that is compatible with Hyper-V and CSV can back up multiple VHD files regardless of how they are arranged on the Cluster Shared Volumes.

    I'd suggest you to do another test , only put a vm on that new created CSV then backup it .

    If it can be successfully backed up , I'd suggest you involve  Nimble and Veeam to check this issue .

    Best Regards,

    Elton


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Wednesday, April 26, 2017 2:46 AM
    Moderator