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VSS snapshot location RRS feed

  • Question

  • Hi

    Last night during a Child Partition Backup on one of my Hyper-V VM, the Host paused all the VM because all the free disk space disappeared.

    During the day I removed a VM freeing about 40GB of disk space so this volume (F:\) was the one with the most free space.

     

    When I canceled the child partition backup, all the free space was available again and I could resume my VMs

     

    I never really understood how the VSS Writer choosed the volume where to store its snapshot (wrong word maybe).

    I had a free unmounted drive in the server, so I set it up, formatted it, now I have new shiny volume with 140GB free, is there a way to force the VSS Writer to use this drive to store the snapshot during the child partition backup, and not to use the volume storing the VM?

    I have multiple volume storing multiple VM, apparently the problem occured when snapshoting the VHD stored on the J:\ Volume, it tried to store it on F:\, so I assume I can tell VSS to go on my new volume K:\

    If there is a way, unfortunately I couldn't find it here and google is not really cooperative with DPM and VSS related questions !!

     

    Thanks in advance for your help

     

    Best regards

    Christophe

    Thursday, October 28, 2010 5:23 PM

Answers

  • You can use the VSSADMIN method as oultined in the article below or simply right click the drive and select "Configure Shadow Copies..." at which point you can highlight the volumes which are suffering from limited free space and then click the "settings" button and then under "Storage area" use the dropdown to change the "Located on this volume:" property to point to the new volume you've configured.

    Vssadmin add shadowstorage
    http://technet.microsoft.com/en-us/library/cc788051(WS.10).aspx


    Cheers, Tyler F [MSFT] - This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, October 29, 2010 9:52 PM
    Moderator

All replies

  • You can use the VSSADMIN method as oultined in the article below or simply right click the drive and select "Configure Shadow Copies..." at which point you can highlight the volumes which are suffering from limited free space and then click the "settings" button and then under "Storage area" use the dropdown to change the "Located on this volume:" property to point to the new volume you've configured.

    Vssadmin add shadowstorage
    http://technet.microsoft.com/en-us/library/cc788051(WS.10).aspx


    Cheers, Tyler F [MSFT] - This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, October 29, 2010 9:52 PM
    Moderator
  • Thanks a lot,

    as the "configure shadow copy" in the drive properties was  listing the drives as "disabled", I didn't know if the "storage area" setting was used or not.

    Now that I took a closer look, it's the schedule that is disabled, not the shadow copy itself... (I'm unfortunately not using the english version windows, which I usually work with, and some of the options and settings are a bit confusing sometimes...)

     

    I used the command line and it worked fine, I'm testing a DPM Child Partition Snapshot in the next few days.

     

    Best regards

    Christophe

    Tuesday, November 2, 2010 12:51 PM
  • Quick update,

    I tested last night and it worked like a charm.

     

    thanks again

    Thursday, November 4, 2010 11:42 AM
  • Ciao All, I have a very similar issue and decided to reopen this thread so to allow googling the whole information...

    Scenario: 4 clustered HyperVs 2008 R2 - A DPM20010 (a different physical server) backing up VMs using child partition snapshots

    A virtual machine (VM1) (2008R2) whose F: drive is a CSV; it has the 25% space free, inside the VM

    The above CSV (named CSV1), from the hyperv point of view, is 100% allocated by a 400GB VHD

    IMHO, the snapshot happens onto the hyperv (let's say: blade1). Where the CSV haven't storage for vss and fires an volsnap id25

    Ok, then.

    Working on blade1 I'm trying to add another volume (SNAP1) for snapshot only. But I cannot see any way to allocate the storage area on the SNAP1 to be used by the CSV1.

    1) must be visible onto the cluster because to be able to fail over nodes

    2) seems VSS Microsoft provide does not support something related to CVS. On blade1 the
    "vssadmin add shadowstorage /for=\\?\Volume{f72d5e93-94de-11df-9ff1-0017a4772404}\ /on=\\?\Volume{2e84a57d-85c6-11e2-851b-0017a4772404}\" returns the error: "Shadow copying the specified volume is not supported" (btw UI just shows the volume itself and cannot be changed)

    Any hints (other then give the CSV1 more spaces :))?
    All the best
    ciao
    pf



    • Edited by pgfiore Tuesday, March 5, 2013 9:10 PM
    Tuesday, March 5, 2013 9:05 PM
  • Ok I worked on the snapshot issue I had and fixed some sharable points. We're talking about: clustered hyperv, CSV, backing up VMs...

    1) the child partition snapshots is taken on the physical server, not onto VM
    1a) All CSVs involved by VM get the "redirect access"
    2) How much free space the physical server "see" on the csv is the point. If it is 100% full (for example due to a vdh) the snapshot cannot be saved (how the VM "see" it does not matter)

    3) I did not find any way to address the snapshot volume elsewhere; normal tools (vssadmin, UI, ecc) do not allow to change volume

    4) of course an hardware provider (instead of the software Microsoft one) could make the job easier, but more expensive

    Summary:
    Leave some free space for snapshots when allocating VM's VHDs

    Ciao
    Paolo


    • Proposed as answer by pgfiore Wednesday, March 13, 2013 2:24 PM
    • Edited by pgfiore Wednesday, March 13, 2013 2:24 PM
    Wednesday, March 13, 2013 2:24 PM