The story so far:
My home machine is in an alcove off my bedroom, it's a IIsi with an external
hard disk, a ZIP drive and a Portrait monitor. That's three fans (one in the
monitor) and three drive mechanisms, and that makes for a lot of whirring in
the middle of the night.

The inspiration:
The ZIP stops its spindle after a little bit of inactivity (ZIPs are strange
little beasts), and that made me think that it wouldn't be a bad idea to stop
the other disks too. The machine is largely idle while I'm trying to sleep, it
would probably be a good thing.

The brilliant idea:
So, my idea was to either stick a timeout in the SCSI routines that would send
a stop unit command to disks that hadn't been used for a while, and then send
them a start unit when they were wanted again.

The immediate benefit to me:
This would mean that one of the disks (the 40Mb internal MacOS only) would be
spun down almost all of the time, which should reduce sound levels somewhat all
by itself. It should also mean that the other disk would only be running when
it was actually in use, which should reduce noise even further.

The questions I have are:
1) Has anyone else played with this at all? It's got obvious benefits for
laptop machines, so I would expect that the code should already be around
somewhere.
2) Does stop unit do what I expect i.e. stop the disk pack?
3) Can anyone see any nasty traps I need to watch for? Do the filesystems keep
the disks constantly ticking, thereby stopping something like this from
triggering?
4) Has anyone got some nice way of quietening the fans without risking heat
damage to my hardware?

If anyone has any answers or general thoughts on this or anything else, I'd be
interested in hearing them (although comments on American politics will
probably go over my head :)

Bernard.
P.S. Sorry about the comic book style, I'm tired and it seems almost funny to
me.