<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Tue, Oct 29, 2013 at 1:21 PM, Anand Avati <span dir="ltr"><<a href="mailto:avati@gluster.org" target="_blank">avati@gluster.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">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).<div>
<br></div><div>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.</div><div><br>
</div><div>Copying Bharata to check if he has other solutions in mind.</div></div></blockquote><div><br></div><div>I see alignment issues and subsequent QEMU failure (pread() failing with EINVAL) when I use a file from XFS mount point (with sectsz=4k) as a virtio disk with cache=none QEMU option. However this failure isn't seen when I have sectsz=512. And all this is w/o gluster. So there seems to be some alignment issues even w/o gluster, I will debug more and get back.<br>
<br></div><div>Jacob - In the first mail you sent on this subject, you mention that you don't see any issues when gluster volume is backed by ext4. Does this still hold true ?<br><br></div><div>Regards,<br>Bharata.<br>
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