Power Management PM7500

[Michael Torrie]

On Mon, 2003-12-29 at 12:15, Mark Alway wrote:
> I have a PowerMac 7500 that has been running an Apache Web server and
> MySQL Database server for several years.  It's still on YDL 2.4 with 
> linux kernel 2.4.18-0.9a. The thing runs non-stop and the hard drive is
> continually spinning.  I'm worried after 2.5 years of non-stop usage 
> that the hard drives will get worn out.  Is there any power management 
> options within YDL 2.4 or 3.0 (Looking forward to upgrading) that will 
> spin down a SCSI hard drive in a 7500 when not in use?  The fan spinning 
> down would also be nice as those older machines are loud.  I would need 
> it to wake on network activity such as a Web GET request or SSH connection.

The idea of spinning drives down comes up from time to time and the
consensus is that it's a bad idea.  Your drives will last far longer (in
a server) if you spin them continuously, rather than spin them up and
down (which will happen many times a day).  After a drive is spun down,
the restart is much harder on the drive mechanically than probably hours
of continuous spinning.  This is because the heads have to come up off
the parked positions (which on older drives is literally a crash into
the platter) and start flying again, the bearings take more force as the
motor torque is applied.    I've lost one hard drive that I know of due
to letting them sleep.  I've run many hard drives near continuously for
years (up to 3 years) without problems.  Hard drive failures will occur,
but you can guarantee that.  The only hazard about spinning drives for
years at a time is that you don't want to turn them off for any length
of time and let them get cold.  I had one drive that spun down and
seized up (this is often due to the bearing getting sticky).  I
understand a nice freezer and a six-inch drop can get them moving
again.  So I suppose it's a trade-off.  But being mechanically inclined,
it hurts me to see drives stop and start all the time.  In a laptop,
such things are unavoidable but the lifespan of a laptop is expected to
be much shorter anyway.

I'll settle for power management on my powerbook 12".  without it, I've
pretty much just got a really expensive desktop machine without any
portability.

Michael


> 
> Thanks,
> Mark
> 
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