ubuntu-server 7.10, what might be preventing my USB drive from sleeping?

[Chris G]

On Wed, Apr 23, 2008 at 05:45:02PM +0200, Nils Kassube wrote:
> Chris G wrote:
> > On Wed, Apr 23, 2008 at 07:17:47AM -0700, David Vincent wrote:
> > > Chris G wrote:
> > > > I have a new ubuntu server 7.10 installation used as a NAS system
> > > > in my garage.  It has a 500Gb external USB drive connected to it.
> > > >
> > > > Something is preventing the external USB drive from going into
> > > > sleep mode, i.e. something is accessing the USB drive at intervals
> > > > such that it thinks it shouldn't power down.  Previously when I
> > > > used the network drive via its ethernet interface (not from the
> > > > ubuntu server system) it did go into sleep mode.
> > >
> > > Since it is shared, is anything accessing that share?  Maybe
> > > something trying to index it?
> >
> > Not that I can think of, it's just a backup with a cron job backing up
> > to it in the small hours.
> 
> If it is just a cron job you could mount the disk before doing the backup 
> and umount it afterwards. Then there should be nothing accessing the 
> drive while there is no backup running.
> 
Now there's a bit of lateral thinking!  :-)

Yes, a good idea, it's *slightly* more involved than that because the
backups run on my desktop machine using the ubuntu-server (with its
USB drive) as a NAS system.  However it shouldn't be at all difficult
to mount and unmount the USB drive using ssh before and after running
the backups.

To test if it goes to sleep I can simply umount the USB drive
'manually' and check if it does power down after a while.

Thank you!

-- 
Chris Green