On Wed, Feb 13, 2013 at 3:44 PM, Theodore Ts'o <tytso@xxxxxxx> wrote:
I suspect this would seriously screw over Gluster, though, and this
wouldn't be a solution for NFSv3, since NFS needs long-lived directory
cookies, and not the short-lived cookies which is all POSIX/SuSv3 guarantees.
Actually this would work just fine with Gluster. Except in the case of gluster-NFS, the native client is only acting like a router/proxy of syscalls to the backend system. A directory opened by an application will have a matching directory fd opened on ext4, and readdir from an app will be translated into readdir on the matching fd on ext4. So the app-on-glusterfs and glusterfsd-on-ext4 are essentially "moving in tandem". As long as the offs^H^H^H^H cookies do not overflow in the transformation, Gluster would not have a problem.
However Gluster-NFS (and NFS in general, too) will break, as we opendir/closedir potentially on every request.
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