Re: [Qemu-devel] The image size of instance VM keeps growing

[Stefan Hajnoczi]

On Wed, May 23, 2012 at 11:47 AM, Charles.Tsai-蔡清海-研究發展部
<address@hidden> wrote:
>        After the VM ran for overnight, the image size for the running VM grew 
> up to 3G bytes.

What is the size of the backing file?  3G is small for a Windows
guest.  Any sector that is written to could cause 64 KB to be
allocated in the image file.

If qemu-img check sees no inconsistencies then it seems the guest is
writing to previously untouched regions of the disk...causing the
qcow2 to grow.

However, the qcow2 file should not grow much beyond its virtual disk
size.  So if you find the qcow2 is 3G but the virtual disk size is 1G,
then there is a bug.  But from what you've posted so far I suspect the
guest is simply writing to the disk.

Stefan