Stefan, Thank you for information. What we worried is an endless growth of the image size. If virtual disk size is the ceiling of the max. image size to be grew, we should not have to worry about this issue.
-----Original Message----- From: Stefan Hajnoczi [mailto:stefa...@gmail.com] Sent: Wednesday, May 23, 2012 8:57 PM To: Charles.Tsai-蔡清海-研究發展部 Cc: qemu-devel@nongnu.org; Jonah.Wu-吳君勉-研究發展部 Subject: Re: [Qemu-devel] The image size of instance VM keeps growing On Wed, May 23, 2012 at 11:47 AM, Charles.Tsai-蔡清海-研究發展部 <charles.t...@cloudena.com> 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
