Hello Dean:

Yes - I initiated the last discussion a last week, as we are experiencing
very similar problems with our SCSI I/O on our AIX ADSM Server - but we have
two 3490E-C22's in a IBM3494 tape library (no 3590's) , and we are also
getting errors like the following in the activity log:

07/23/96 19:27:18    ANR8303E I/O error on drive TAPEDRIVE1 (/dev/rmt1)
                      (OP=LOADDISPLAY,

 SENSE=00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00-
                      .00.00.00.00.00.00.00.00.00.00.00.00.00.00.00).

Also - these errors always happen in pairs, where if the error 1st occurs on
one of the tape transports it immediately triggers the same error on the
other tape transport on the same SCSI controller card, and both tapes are
marked as "read-only" - in error state.

Currently, the IBM hardware techies are reviewing the trace dumps I sent,
and they suspect an I/O timing problem between the device driver and the
micro-code on the SCSI controller.
They also ensured that (in smit) the "Allow Device to Dominate SCSI Bus
Cycles" was set to "no" - which it was.  However the problem still
happens....

Another possibility:
Mark Mapes (PG&E) had a similar problem, especially during heavy drive
usage, & he found that they could NOT use External Bus SCSI ID's with a
value of zero or one (valid addresses had to be in range 2-7) - they were
using a value of 1.   - Something to check on anyway...

PMR still open... (& hoping!)

Later -
Roland Macuzzi
Email: macuro AT edc3.edc DOT ca
Export Development Corporation
 ----------
From: owner-adsm-l
To: Multiple recipients of list ADSM-L
Subject: Tape I/O Errors
Date: Thursday, July 25, 1996 8:48AM

I believe there was a discussion of this recently - if anyone can help I
would appreciate it.

I am getting intermittent errors from my tape drives which cause the volume
to be marked read-only. These are SCSI attached 3590 drives running off an
AIX server.

I seem to remember someone talking about SCSI errors - any help??

Here is my error text:

07/24/96   06:00:35  ANR8337I 3590 volume 002436 mounted in drive
TAPEDRIVE00
                      (/dev/rmt0).
07/24/96   06:26:19  ANR8311E An I/O error occurred while accessing drive
                      TAPEDRIVE00 (/dev/rmt0).
07/24/96   06:26:19  ANR1411W Access mode for volume 002436 now set to
                      "read-only" due to write error.

 -------------------------------------------------------------------
  Dean Roy                           Email: DEAN AT UWINDSOR DOT CA
  Systems Programmer                 Voice: (519)253-4232 Ext 2763
  University of Windsor              Fax  : (519)973-7083
 -------------------------------------------------------------------