[comp.unix.sysv386] Second Disk Controller on ATT SVR3.2.3--Can I Do IT????

jmcook@jorel.APLDMT.COM (joel m. cook) (06/20/91)

I haven't seen this asked in the group and it's not on the
FAQ list, so I thought I'd try.

The subject is the gist of the question.  It's clear from the
man pages that AT&T SV/386 (3.2.3) has at least *some* support for
a second hard disk controller and disks.  The "diskadd" command
makes reference to device special files of the form:

	/dev/dsk/[cid]jsk 

where 'i' is the controller number (0 or 1), 'j' is the driver number and
'k' is the partition number.  The standard files would be something
like /dev/dsk/c0d0s1 for the root partition, but the "c0d" is omitted
for the first controller.

I'm trying to figure out how or even if this implementation can be done.
Does the bios at boot time have to support the second controller, or is
that irrelevant since UNIX does its own thing?  Clearly the controller
would need another interrupt, but that's not a problem (I think) since
I have several spare.  At first glance, this all seems reasonable to
do by setting up the appropriate /etc/conf files, rebuilding and going, but
I'd like to know if anyone else has tried it, and if so, with what results.

Thanks in advance and I'll post if there's enough interest.
-- 
			Joel M. Cook
			jmcook@jorel.apldmt.com

nfp@cbnewsm.att.com (nels.f.poulsen) (06/28/91)

Two controllers using ATT SVR3.2.3???  Heck I haven't been very successful getting
one WD1007 and two esdi drives to work very well.  I do the add disk via face
and it seems to go well until setting up the file systems (tmp and usr3).  It
takes over 2 minutes for a 5meg tmp and about half hour for the 50 meg usr3.

Once the diskadd is complete, any and all accesses to the second hard drive take
incredible amounts of time and locks out the currect user (and possibly the 
entire system; its a one user system right now) for a long, long time (anywhere
from 15 seconed to over one minute).  The second disk doesn't seem to be doing
anything but hanging the system; the activity light goes on, but I cant hear any
particular head movement or any sign that some io is being done.

Both disks are partitioned with a dos partition as the first one on the drive
and this wait problem doesn't happen when using dos.  The disk paramneters seem
to be set correctly, so I'm not sure what might cause this problem.  The hard
disks are both Seagate (Imprimus) ESDI and are 309 and 159 megs respectively.

Any help would be appreciated...

Nels Poulsen
(908)957-2611