Attaching non-sun SCSI drives to a SparcStation

[Gert Poletiek]

We are trying to hook up SCSI drives not bought from Sun to our
Sparcstations. Reason: we can buy between 2 and 3 times more disks this
way.

The problem we encountered is the following. During the last phase of
formatting the disk (a CDC Wren IV) the disk label and backup label are
written to the disk. The label is written correctly (since it is written
onto one of the first blocks of the disk), but writing the backup label
fails. We get a SCSI error back from the disk saying that the format
program tried to write beyond the end of the disk.  We tried changing the
format parameters in /etc/format.dat but that didn't help either. If
nsyl=x, acyl=y and pcyl=x+y we always get 'No media error on cylinder x'
once the backup label is being written.

We've experienced the same problem with other SCSI disks with an embedded
controller. Sun disk with ESDI/SCSI convertor boards in them do not have
this problem.

I reported this problem to Sun in Holland and they told me: Sun ships its
own CDC Wren disks.  They couldn't tell me what Sun had changed with
respect to the 'normal' CDC Wrens. The only thing they could have changed
is the ROM on the embedded SCSI controller board.

Does anyone have a solution to this problem?