[sheepdog] Bug in v0.4.0 ? get_sha1_file(80) PANIC: Operation not supported

[Christoph Hellwig]

On Fri, Jul 13, 2012 at 10:04:56PM +0200, Jens WEBER wrote:
> found it, node 2 only gateway has not a file system with user_xattr option, /var/lib/sheepdog was on a aufs
> with ext4 and option user_xattr it works as expected
> is this really necessary for a only gateway node?

Currently farm always writes a sha1 snapshot file after each recovery
process.  I can't see how that's needed on a pure gateway, but maybe
someone who knows farm better can comment?

Either way it would be good to try a simple listxattr operation during
startup and abort the startup than having this panic.