Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!lll-winken!arisia!cdp!steve
From: steve@cdp.UUCP
Newsgroups: comp.unix.i386
Subject: Re: Disks Hang Under 2.0.2 SCSI
Message-ID: <654400004@cdp>
Date: 13 Dec 89 20:04:00 GMT
References: <654400003@cdp>
Lines: 70
Nf-ID: #R:cdp:654400003:cdp:654400004:000:2075
Nf-From: cdp.UUCP!steve    Dec 13 12:04:00 1989


This is a followup on a posting I made a couple days ago, about
being able to easily crash interactive 2.0.2, by reading from
3 SCSI disks simultaneously (running an aha1542a controller).

I have replicated the crash on a compaq 386/20e.  This was
sufficient for interactive to "validate" the bug report --
i.e., they consider it a driver bug.  There is no committment
on their part to fix it, but the L.A. support person continues
to be communicative and sympathetic.  Hollis doesn't return
my phone calls.

We have now come up with a program that will crash 2.0.2 with
just 2 SCSI disks and 1 SCSI tape.  I suspect that this is a
more standard configuration.  The tape drive is an archive
2150s (with ROM revisions as recommended in the interactive
1.0.6 release notes).  The disks are CDC 94161.  Alas, this
program takes between 10 minutes and 1 hour to hang the disk
driver (as opposed to the 3 disk version, which hung the driver
in < 2 seconds).

Does anyone have experience running the future domain
controller with 3 or more SCSI disks ?  We are considering
replacing our SCSI disks with 2 high capacity ESDI disks (> 600
MB), running the Western Digital wd1007v-se2 (replacement for
WD1007).  Does anyone have experience (good or bad) with such a
configuration ?


Steve Fram
Chief Programmer
Community Data Processing (CdP)
{pyramid, hplabs, ...}!cdp!steve

-------------------------------- cut here --------------------------------
:
# crashix2.sh
#
#   crash interactive 2.0.2 running just 2 SCSI disks and 1
#   SCSI tape.
#

# disk parameters
dd_dev1=/dev/rdsk/0s1			# root
dd_dev2=/dev/rdsk/1s3			# one partition on disk
dd_count=1000
dd_bs=128k

# tape parameters
tape_dev=/dev/ct
tape_bs=32k

while :
   do	echo "New dd loop..."

	dd if=$dd_dev1 of=/dev/null bs=$dd_bs count=$dd_count 2>/dev/null &
	ddp1=$!
	dd if=$dd_dev2 of=/dev/null bs=$dd_bs count=$dd_count 2>/dev/null &
	ddp2=$!

	while kill -0 $dd_p1 || kill -0 $dd_p2
	   do	sleep 10
	done 2>/dev/null

done &

while :
   do	echo "New tape loop..."
	dd if=$tape_dev of=/dev/null bs=$tape_bs
done &