external USB disk

[R Kimber]

For some time I have had a USB disk that remained unmounted except when a
backup script ran, or I specifically mounted it. After a certain idle time
the disk would spin down and remain quiet.  Recently, however, I've noticed
that something is causing the disk to spin up every 5 minutes, even though
it is unmounted.

Does anyone know what might be causing this, and what I might do to restore
the previous behaviour?

The drive is a Seagate 300MB ST300601U2-RK and I'm using Ubuntu 12.04 with
Mate.

- Richard.
-- 
Richard Kimber
Political Science Resources
http://www.PoliticsResources.net/