Subject: Re: Seagate SCSI write-back drive cache
To: None <netbsd-users@NetBSD.ORG, chuck@dworkin.wustl.edu>
From: Laine Stump <laine@MorningStar.Com>
List: netbsd-users
Date: 03/24/1997 10:30:33
Sorry, I read this through a mail->news gateway, forwarded the message
back to my email for archiving, and then forgot the original mailing
list it was sent on. Hopefully this one is close enough.

> On Sat, 22 Mar 1997 23:00:18 GMT, chuck@dworkin.wustl.edu (Chuck Cranor)
> wrote:

> >you need to change a value on "mode page 8".  what you have to 
> >do is get the "scsi" program compiled and run the following command:
> 
> >./scsi -e -f /dev/rsd0d -m 8 -P 3
> 
> >and change WCE to "1".

Just how safe is this even in the case where you have a UPS? Does the
drive properly send the sector to a spare if it encounters an error
while trying to write? The one Seagate document I found about the option
recommended not setting it if you were running a multitasking OS.

> >I believe the "scsi" command is from FreeBSD.   However, it has been
> >ported to OpenBSD, so I just grabbed all the necessary pieces and 
> >pulled it over to NetBSD (it doesn't require any kernel changes).
> >get ftp://dworkin.wustl.edu/pub/scsi.tar.gz if you want my port of
> >the OpenBSD version of "scsi" (includes i386 binary).

A couple of gotchas:

1) there is a place in scsi.c where the standard place for the
scsi_modes file has been overridden to point to
/users/chuck/something. You'll need to remove that before it will work.

2) make install doesn't install the scsi_modes file - copy it to
/usr/share/misc.