> > Looks like what is happening is that qemu performs ioctls() on the backend to query logical_block_size (for direct IO alignment). That works on XFS, but fails on FUSE (hence qemu ends up performing IO with default 512 alignment rather than 4k). > > Looks like this might be something we can enhance gluster driver in qemu. Note that glusterfs does not have an ioctl() FOP, but we could probably wire up a virtual xattr call for this purpose. > > Copying Bharata to check if he has other solutions in mind. > > Avati > > > > On Tue, Oct 29, 2013 at 12:13 AM, Anand Avati <avati at gluster.org> wrote: >> >> What happens when you try to use KVM on an image directly on XFS, without involving gluster? >> >> Avati >> Avati- Thanks for finding this. Unfortunately, my KVM hosts (gluster clients) either don't have local disks or their local disks have 512 byte sectors. Let me know if I can provide any additional information. -Jacob
