Subject: Re: test of new powerdown facility
To: None <gwr@NetBSD.ORG>
From: Wilko Bulte <email@example.com>
Date: 06/09/1998 21:25:09
As firstname.lastname@example.org wrote...
> > From: Jason Thorpe <email@example.com>
> > Date: Tue, 09 Jun 1998 10:36:33 -0700
> > > I hasten to point out that I have a Quantum Fireball 1080S in this beast,
> > > and this may be a HDA cache-flush issue; Apple had this problem with these
> > > disks a few years ago. Is there an explicit SCSI command to force a disk to
> > > flush its cache to permanent storage?
> > I think there is, but I can't remember for certain... this would be good
> > for a shutdownhook... each SCSI disk could register one, and ensure that
> > it has flushed its cache.
> How about sending a SCSI "stop" command? (i.e. spin down)
In general: flushing caches of disk drives is a dark and dangerous area.
I've discussed this with one of our diskdrive gurus and the consensus is
that you cannot really trust writeback caching on disks. Different f/w
revs on a single type of drive may give different results.
| / o / / _ Bulte email: wilko @ yedi.iaf.nl
|/|/ / / /( (_) Arnhem, The Netherlands WWW: http://www.tcja.nl
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