auto-mounting ZFS snapshots

[Freddie Cash]

On Mon, Dec 6, 2010 at 1:13 PM, Patrick Proniewski <patpro at patpro.net> wrote:
> On 6 déc. 2010, at 18:20, Freddie Cash wrote:
>
>> FreeBSD automounts the "hidden" .zfs filesystem hierarchy where
>> snapshots are "stored" automatically.  No need for amd.
>
> The zfs man page reads:
>
>       File  system snapshots can be accessed under the ".zfs/snapshot" direc-
>       tory in the root  of  the  file  system.  Snapshots  are  automatically
>       mounted  on demand and may be unmounted at regular intervals. The visi-
>       bility of the ".zfs" directory can be controlled by the "snapdir" prop-
>       erty.
>
> "may be unmounted at regular intervals" <-- what about this? Do I have to create a periodic script that'll unmount snapshots? And if so, how can I make a script that'll unmount only snapshots mounted for over, say, 1 hour?

If you don't want the output of "mount" to be cluttered with ZFS
snapshots, then you can manually clear it out with something like:

mount | grep <fs-name> | awk '{ print $1 }' | xargs sudo umount

Replace <fs-name> with the ZFS filesystem name as shown in the output
of mount.  If needed, you could put that into a periodic script or
cronjob.

However, it shouldn't hurt things to have all the snapshots mounted.
We have 205 snapshots mounted on our backups server without any issues
so far.

-- 
Freddie Cash
fjwcash at gmail.com