[comp.sys.sequent] SCSI disks for Balance 8000

stanw@zeus.unomaha.edu (01/03/91)

We have a Sequent Balance 8000 and need more disk space. Does anyone have
experience with using SCSI disks other than the 72MB drives supported by
Sequent? Specific brands and experiences would be helpful.

Stan Wileman, Math/CS Dept., U. of Nebraska at Omaha
cs002@unocss.unomaha.edu (137.48.16.1) -or-
stanw@zeus.unomaha.edu (137.18.1.1)

pen@lysator.liu.se (Peter Eriksson) (01/03/91)

stanw@zeus.unomaha.edu writes:

>We have a Sequent Balance 8000 and need more disk space. Does anyone have
>experience with using SCSI disks other than the 72MB drives supported by
>Sequent? Specific brands and experiences would be helpful.

Well, I've just recently tried to add a CDC (Seagate) Wren V (700MB) SCSI
disk to our Balance 8000. It didn't work. Seems the SCED board isn't
completely compatible with the Wren's SCSI bus... We have though been able
to add a number of ST412/ST506 (normal IBM PC type disks) disks to the
Adaptec ABC5500 controller that normally controls only the 72MB Fujitsu
disk. Just plug them in, format them with the 'formatscsi' program and off
you go. The disks will show up as sd1, sd2 .. We are currently running a
MicroPolis 1325 (some 70MB) an old Seagate ST225 (20MB), and we even had a
BASF 6188 (some huge 12MB:s! :-) installed in it (in addition to the Fujitsu
disk). You may have to add entries in the /etc/disktab database, but that is
no major problem. (We have had some trouble due to an overloaded PSU in our
Balance that caused some very strange errors that started to show up when we
added more disks to it - seems the PSU isn't (wasn't?)  designed to take 12
processors, 10MB of RAM, 2 Multibus adapters and a SCED card at same time....
It accumulates to some 200A on the +5V line, and the PSU is rated at 150A ...)

Please let me know if you have some more specific questions. Who knows, I might
even be able to answer them.. :-)

--
Peter Eriksson                                              pen@lysator.liu.se
Lysator Computer Club                             ...!uunet!lysator.liu.se!pen
University of Linkoping, Sweden                               "Seize the day!"