zfs discuss - Aug 2009 - turn off an usb drive

Probably a very easy question for ZFS experts. I have an external USB
drive running 24/7 but would like to turn it off once in a while.
It is on ZFS.

Is it enough to umount it and tunr off the drive or do I have to
*export* the zfs filesystem first and later import it again?

-- 
Dick Hoogendijk -- PGP/GnuPG key: 01D2433D
+ http://nagual.nl/ | SunOS 10u7 5/09 | OpenSolaris 2009.06 rel
+ All that''s really worth doing is what we do for others (Lewis Carrol)

On Sat, 22 Aug 2009, dick hoogendijk wrote:
> Probably a very easy question for ZFS experts. I have an external USB
> drive running 24/7 but would like to turn it off once in a while.
> It is on ZFS.
>
> Is it enough to umount it and tunr off the drive or do I have to
> *export* the zfs filesystem first and later import it again?
You should export the zfs pool.  Zfs does not like devices to be 
completely turned off.  Perhaps someday it will power manage devices 
so that they are automatically turned off and turned back on when 
needed.

Bob
--
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/