No announcement yet.

Snapshot problems during VCB

  • Filter
  • Time
  • Show
Clear All
new posts

  • Snapshot problems during VCB


    First of all, excuse me for my bad English.....

    I have this configuration: 3 host ESX 3.5 with a fiber channel SAN, a VC, vcb and BackupExec 12 on a physical server: all updated to the latest versione.

    When i run the full backup of VM guest with BackupExcec using the VCB integration, sometime the VM's have a problem: in one case one VM (a terminal server with 60 users) was frozen for 15 min, the VIC displayed "time out error" and the backup process ended. This appened imeediately after the beginning of snapshot task. I must rerun the backup process after shutting down the guest OS to prevent this problem.

    In other cases, a full backup process of a Windows Domain Controller Guest VM, causes a multiple error in guest event view, especially in the AD read/write operation, so the client can not authenticate. Even here, immediately after the beginning of the snapshot. The backup proceeds normally, but the problem on the guest os is resolved only after a reboot.

    Other VM (10 out of a total of 15), work fine without prolems.

    I think that the problem was in the snapshot operation, but non ever and not on the same VM.

    Is there someone who has had similar problems?

    You give me suggestions?


  • #2
    Re: Snapshot problems during VCB

    We had what appears to be a similar with esXpress backup of VMs on ESX 3.5.0.

    Based on the feedback from the folks at PHD (writers of esXpress) there appears to be a bug with ESX SnapShot processing if the SnapShot is requested with Guest OS Quiesce.

    This intermittently causes the Guest OS to hang for an extended period when the SnapShot is requested. The SnapShot request returns a Failed status to the calling user, but the SnapShot commonly gets created. Because the calling program gets an error it is unaware that the SnapShot actually got created so never attempts to remove the SnapShot which must be removed manually through the VI Client.

    For us the problem has not occurred since we changed to requesting SnapShots without Quiesce of the Guest OS.

    It appears that SnapShot with Quiesce may actually work for ESX releases 3.5.0U3 and beyond and there seems to be some documentation suggesting that VMware fixed the VSS write in the VM Tools? We have not tested this yet.

    As to VCB, we do not use this software but I am assuming it will use standard calls to ESX to perform SnapShots so it will be subject to the same ESX issue?