none
Moving virtual machine Pagefiles to seperate VHD for exclusion by DPM RRS feed

  • Question

  • Hi,

    I have read the MS documentation regarding excluding pagefile churns from virtual machines to increase performance of backups and reduce storage space required and I would like to implement this within our environment.

    http://technet.microsoft.com/en-us/library/jj721498.aspx

    However, when I move the pagefiile from the system disk onto a seperate VHD I get the following warning:

    "If you disable the paging file or set the initial size to less than 400 megabytes and a system error occurs, Windows might not record details that could help identify the problem. Do you want to continue?"

    As I understand things this means that I may not get a crash dump if a BSOD occurs. Is this correct, and if so how can I mitigate? How have others managed this scenario, do you just live with the fact that you won't get a dump file in the event of a problem?

    Thanks in advance.


    Microsoft Partner

    Thursday, July 24, 2014 10:01 AM

All replies

  • "If you disable the paging file or set the initial size to less than 400 megabytes and a system error occurs, Windows might not record details that could help identify the problem. Do you want to continue?"

    AFAIK, all you need to do is to ensure that the separate drive does have a paging file on it, and then this message can be ignored.

    Once the the page-file for a virtual machine is moved to a different VHD, you should exclude it from DPM by using the Set-DPMGlobalProperty cmdlet.

    Otherwise, you can use backup tools that can do page-file exclusion in automatic fashion, like Veeam, for instance. We use the said software in our environments and pretty happy with the functionality it provides.

    Kinds regards, Leonardo.

    Friday, July 25, 2014 2:26 PM
  • If you keep page file for more than 400MB, you won't see this error. Is there any reason why you want to keep it below 400MB?

    General guidance is that Page file should 1.5 times the RAM allocated.

    Tuesday, August 5, 2014 12:36 PM
    Moderator
  • If you keep page file for more than 400MB, you won't see this error. Is there any reason why you want to keep it below 400MB?

    General guidance is that Page file should 1.5 times the RAM allocated.

    I have the page files greater than 400MB as it is still system managed, only that I have moved the pagefile off the system disk onto a dedicated disk so it can be excluded from DPM backups but still get the message.

    Microsoft Partner

    Monday, August 11, 2014 10:28 AM
  • Windows can only guarantee it can write to the page file if it's on the system volume disk.  So if you move it, you get the popup.  So you can ignore the message for now and whenever you want to troubleshoot a reproducible errors, you can create a page file of size at least 400MB in system volume disk to get the crash dump.
    Tuesday, October 7, 2014 9:00 AM
    Moderator