File VHD is always growing RRS feed

  • Question

  • Hi All,

    I have  Hyper-V windows server 2008 R2 with 2 virtual server installed.

    Vhd file of one virtual server is always growing whereas there was no file growth in the virtual server,  so I always compact the vhd, but the vhd file will grow again.. again.. again...

    How to know what the cause?


    Nana Sutisna

    Wednesday, October 12, 2016 11:37 AM

All replies

  • There can be several reasons. 

    1. by default, Windows is going to be writing to the drive, various files, swap memory, etc, which will cause it to grow.  Windows by default will avoid overwriting clusters that have been deleted.

    2. utilities on host that are not VM aware and are scanning the vhd, like AV, backups, etc, can cause the vhd to expand.

    Wednesday, October 12, 2016 4:00 PM
  • Hi Smjain,

    No amazing file growth in the virtual server, it just grow normally.

    The problem is the vhd file have been growing is very big size, over 100 GB per week.

    I already exclude the vhd file from antivirus scanning, but the problem still occurred.

    Could you guide me how to find the root cause?


    Nana Sutisna

    Thursday, October 27, 2016 12:03 PM
  • What's being stored on the VHD?  Logs, SQL databases, etc? Lots of users writing to it.  Are you using checkpoints?

    Please describe in detail what the server is doing.

    Thursday, October 27, 2016 4:21 PM
  • Hi smjain,

    The virtual Server have been using for SQL Database. Default installation for SQL database on virtual drive C, but the mdf file and log file already moved to virtual drive D.

    The problem is the vhd file of virtual drive C, when the vhd file have big size, I checked the size of virtual drive C is normal. the size of vhd file is bigger than the size on virtual drive C.


    Nana Sutisna

    Friday, October 28, 2016 8:15 AM
  • Generally, if the VHD is growing beyond its limits, something on the host is affecting the VHD.  Does your host try to backup the VHD?
    Friday, October 28, 2016 4:16 PM
  • I backup this vhd once per three month, but the problem every week.

    Do you know how to find the process that caused this problem?

    Monday, October 31, 2016 6:29 AM
  • The best suggestion I can give you at this point, is to repost in the correct Hyper-V forum here:


    With as many details as possible.  Make sure to include both the host and guest OS and any software running on the host OS.

    Tuesday, November 1, 2016 4:52 PM
  • Ok, I have post this point to Hyper-V forum ---> https://social.technet.microsoft.com/Forums/windowsserver/en-US/5c52c0ee-f291-44e2-87a0-acc2a03c29d9/file-vhd-is-always-growing?forum=winserverhyperv


    Nana Sutisna

    Tuesday, November 8, 2016 6:11 AM