SUMMARY: SCSI error information

Date: Tue Sep 16 1997 - 14:00:33 CDT

The original question:

Anyone have an what the following console message means?:

WARNING: /iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000/esp@f,800000 (esp0):
        SCSI bus MESSAGE OUT phase parity error

Bad termination? Cable length (doubt it - I've had even more devices on the
chain - all cable lengths are short)? Seems to occur when the SCSI bus is
relatively loaded.

SPARC 10, Solaris 2.5.1, Sun 424MB boot drive, internal Sun 2.1GB, external
Sun CDROM, 4mm tape drive, 150MB 1/4" tape drive.

Thanks - summary to follow..


..and the answers:

From: Sean Ward <>

Hi Brian. When I've seen this it's usually one of three problems:
1. Bad cable
2. Bad terminator
3. Cable length

Since you've ruled out #3, I'd start swapping cables and see what happens.

From: Ira Childress <>

I've seen this problem in the past, and, if memory doesn't fail me, the
problem was related to the disks on-board controller going bad. The other
time (s?) I think I saw it was when putting a differental disk on a single
ended SCSI chain.

The latter appears constantly, the former only occassionally. I don't know
if you're getting it all the time or just once in awhile.

From: Jim Harmon <>

My bet is that the 2.1 GB device is probably FastWide, and the rest of
your SCSI devices are narrow or Fast-Narrow SCSI.

IF that's the case, then the adapter that interfaces your 2.1GB drive to
the SCSI chain may be causing the device to work an slow SCSI speeds, or
one of the tape devices is a slow scsi device and the chain doesn't
slow-down from fast-SCSI on ocassion when you spin up that tape drive.

If they are all Narrow SCSI then it's MOST likely the 150MB Tape drive
is a slow-SCSI device.

From: Rick Reineman <>

It would be a good idea to ditch the 424 disk. By themselves they
are OK, but you are mixing it with a Fast SCSI device (the 2.1GB).
You would get a major performance boost if booting from the 2.1GB.
The SS10 does have a fast SCSI interface, the 424 is not fast SCSI.

The tape and CD devices are usually OK mixed with a fast SCSI device,
especially if they are Sun. Ideally you could get a cheap SCSI
host adapter and put your tape devices on it.

You might try disconnecting various devices to isolate the problem
should it persist.


I suspected the fast/wide/narrow/slow matrix might be a cause, since the
problems started when I was doing backups with larger block sizes to the
4mm drive (which I should have mentioned). I'll toss the 1/4" tape drive
off the chain (and check the cables just in case), but everything else has
to stay; after all my pleading, my boss still won't go for an Ultra II
with 512MB and a few 4.2GB drives....

Thanks to all above for their comments...


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