On Sat, Apr 14, 2012 at 2:31 PM, Prateek Sharma <[email protected]> wrote: > I am writing to ask whether there is any possibility of silent data > corruption with virtIO/qemu. > My files inside the guest are getting zeroed out. Specifically, bytes > 512 to 4096 on some files are being zeroed out. (some 60K files out of > 5Million are showing this so far). The virtual disk is a file on > ext4 (size of file is 1TB), and i am using virtio, aio-threads=native, > and cache=none. The disk having the virtual disk is on mdadm > raid1---so i am guessing possibility of disk corruption is low
Did you check the corruption by mounting the image file on the host while the VM is not running? This we you can be sure that there is no bug that causes the guest to "see" zeroes. If you see the zeroes inside the guest we can't be 100% sure that the image file itself contains them. Can you describe the guest configuration? Guest operating system? Application/mail server? Which files are being corrupted? Is I/O constantly being issued by the guest or does the corruption appear even when the files are not being accessed? Basically anything that can help spot a pattern here. Stefan
