I think I finally made some progress on this bug! I noticed that all disks in my gluster server(s) have 4K sectors. Using an older disk with 512 byte sectors, I did _not_ get any errors on my gluster client / KVM server. I switched back to using my newer 4K drives and manually set the XFS sector size (sectsz) to 512. With the manually set sector size of 512, everything worked as expected. I think I might be hitting some sort of qemu/libvirt bug. However, all of the bugs I found that sound similar[1][2] have already been fixed in RHEL6. Anyone else using XFS backed bricks on 4K sector drives to host KVM images in RHEL6? -Jacob [1] https://bugzilla.redhat.com/show_bug.cgi?id=608548 [2] https://bugzilla.redhat.com/show_bug.cgi?id=748902
