Re: SCSI disk driver module spin-up
Andrew Walker (andy@lysaker.kvaerner.no)
Tue, 27 Feb 1996 09:24:44 +0100 (MET)
Bryn Paul Arnold Jones wrote:
>
>
>
> On Sun, 25 Feb 1996, Albert Cahalan wrote:
> > Well, what number of hours running causes the same wear as one spinup?
> > Determine this (buy 10000 drives and run them...), then spindown at
> > 10% of that time because most drives are not well cooled.
> >
> > I do think 26 hours is good. If you do not use the disk for 26 hours,
> > it is likely that you will not use it again any time soon.
> >
> > (about partition tables: you don't _need_ to read them all)
> >
> Hmm, I wouldent think reading the partition table would be a problem,
> don't SCSI disks spinup at power on anyway ?
> Bryn
> (I don't own any SCSI stuff, but I am looking at getting some ....)
>
Oh no, by golly. Not if you set the little jumper that's normally
called 'motor start' or 'motor enable'. Then they wait for the controller
to access them before spinning up.
Usually there's also a jumper called 'delay start' that means that
even when accessed it waits typically SCSI ID * 10 seconds before
spinning up (so if you've got 7 SCSI disks on the bus ID0 spins up
immediately, #1 spins up after 10s, #2 after 20s and so on).
-Andy
--
Andy Walker Kvaerner Engineering a.s.
Andrew.Walker@lysaker.kvaerner.no P.O. Box 222, N-1324 Lysaker, Norway
......if the answer isn't violence, neither is your silence......