Re: mount -a vs glusterfs

[mlelstv%serpens.de@localhost (Michael van Elst)]

kab00m%lich.phys.spbu.ru@localhost (Dima Veselov) writes:

>and one make "mount -a" several times - filesystem will
>be mounted over and over

>Filesystem                  Size       Used      Avail %Cap Mounted on
>/dev/dk0                    993M       173M       770M  18% /
>gfs01:/gva                  3,9T        45G       3,9T   1% /gva
>gfs01:/gva                  3,9T        45G       3,9T   1% /gva
>gfs01:/gva                  3,9T        45G       3,9T   1% /gva

>unlike FFS filesystems which are not mounted again if
>mounted before. Is it a bug and where it can reside?

You can mount several filesystems on top of each other. Usually
only the last mount is visible unless you mount with -o union
where the next filesystems on the stack shines through.

Mounting the same local filesystem like FFS twice fails because
the underlying disk device only allows a single opener.

But this doesn't happen here because the mount command, when started
with -a option, checks the existing mount list if a mount point is
already used by a filesystem of the same type. If you run mount
with additional option -v, you will see which "already mounted"
filesystems are skipped.

Apparently this check fails for glusterfs and there is no
other obstacle that prevents further mounts, so you get
multiple mounts.

The source suggests that glusterfs uses the filesystem type
"puffs|perfuse|fuse.glusterfs" and the check above strips
the "puffs|" prefix. Sounds like lots of magic, but not
enough to make the check work.

Please run 'mount' or 'mount -v' to see what filesystem type
is actually recorded. "glusterfs" or "puffs!glusterfs" should
be fine.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."