On 3/21/2012 12:04 PM, Timo Sirainen wrote:
The problem is most likely the same as with NFS: Server A caches data -> server B modifies data -> server A modifies data using stale cached state -> corruption. Glusterfs works with FUSE, and FUSE has quite similar problems as NFS.
With director you guarantee that the same mailbox isn't accessed simultaneously by multiple servers, so this problem goes away.
If using "real" shared storage i.e. an FC or iSCSI SAN LUN, you could use a true cluster file system such as OCFS or GFS. Both will eliminate this problem, and without requiring Dovecot director. And you'll get better performance than with Gluster, which, BTW, isn't really suitable as a transactional filesystem, was not designed for such a use case.
-- Stan