mesh:lost arbitration error

Subject: mesh:lost arbitration error
From: Merle F. McClelland (
Date: Thu Jun 08 2000 - 13:00:36 MDT

I have a Sony SDT-9000 DAT drive daisy-chained to the end of my SCSI
bus on a PowerBook G3 (1999 model). The other device on the chain is
a 9 GB IBM hard drive, which is my boot disk for Linux. I'm running
YDL version 2.2.6-16bpmac, and I am not using the internal ATA drive
at all in the Linux environment.

I've discovered that during long tape I/O sequences to /dev/st0, the
messages file starts recording "mesh: lost arbitration" errors. This
occurs with all tape I/O software (tar, dump, bru, taper, cpio), and
with any tape that I use. Performing a verify or read with these
programs eventually fails with a Read I/O error, and the error occurs
at the same place on the tape during successive reads for a given
archive, so I believe that the error actually occurred during the
initial write operation. If I repeat the archive operation the error
will occur at a different place, so it doesn't appear to be a media

This same drive works fine on the Mac using Retrospect for backups,
and I clean it when prompted to do so by Retrospect. The drive is not
used often for Linux (maybe once a month). I can recycle the tapes
used for Linux backups and use them for Retrospect and I have no
problems. Since this has occurred with multiple tapes I suspect a
SCSI problem (driver or hardware).

The hard drive is working fine alone - no problems at all, so I
suspect that it is a problem when there are two SCSI devices on the
bus, both being accessed by the Linux system. I've tried different
terminators and I'm using an active one at the present, but no change
in symptoms. The cables between the PB and the HD, and the HD and the
DAT are new 18" shielded cables. I've reversed the order of the
devices (DAT first, HD second) with the same results. Using other
SCSI devices under MacOS appears to work fine as well, so it looks
like a Linux driver issue.

I've searched the net looking for anything that might apply but
haven't seen any mention of this lost arbitration error message.
Pointers to patches, FAQs, whatever, will be greatly appreciated.

                                                - Merle

   Read about my TransAmerica Bike Ride '97, Storm Chases '98, '99 and
             '00 at:

"Distant roads are calling me" - Guess Who _______________________________________________________________________

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