Subj : Re: DDS4 Tape Errors
To   : comp.os.linux,comp.periphs.scsi
From : David Kinsell
Date : Thu Jul 01 2004 02:02 pm

I'd try a brand-new tape.  8 months of daily backups is a heck of a lot
of useage per tape, unless you've got large numbers in the rotation.

Also, cleaning cartridges have a fixed number of uses built into them,
make sure they're still good.

-Dave


"Nick Barendt" <nickbarendt@gmail.com> wrote in message news:4502b77a.0406230712.6e12ffb2@posting.google.com...
> I have a Dell PowerEdge 2600 running RH9 (2.4.20-30.9) with a PERC
> 4/Di "MegaRaid" RAID/SCSI controller.  There is a Dell PowerVault 100T
> DDS4 (aka Archive Python 06408, firmware rev 9100) SCSI tape drive on
> the secondary SCSI channel.  The tape drive is the only device on the
> SCSI channel and there is a terminator on the end of the cable and the
> controller's termination is enabled on the other end.
>   The system has been running for about 8 months with no trouble,
> using Amanda to perform daily backups.  Recently we started having
> some tape drive trouble, though.  Initial problem was that some error
> during the backup would lock up the entire machine - everything.  Dell
> technical support suggested forcing the SCSI channel speed down to
> Fast from the default 320 MB/s.  That seems to have fixed the the
> lockup problem, but then we started seeing other drive errors.  Dell
> swapped the tape drive, cable, and terminator under warranty (Yay
> Dell!), but the errors have continued.  They seem to be intermittent.
> Some times the backup runs fine, other times it fails with errors like
> this:
>
> Jun 19 02:23:43 kernel: st0: Error 250400f0 (sugg. bt 0x20, driver bt
> 0x5, host bt 0x4).
> Jun 19 02:23:44 kernel: st0: Error with sense data: Current st09:00:
> sense key Unit Attention
> Jun 19 02:23:44 kernel: Additional sense indicates Power on,reset,or
> bus
> device reset occurred
> Jun 19 02:23:44 kernel: st0: Error on write filemark.
>
> I haven't been able to decode the Error code of 250400f0.  The backup
> is failing relatively early, somewhere less than 3GB of an 18GB
> backup.
>
> We keep up with the cleaning tapes and the tapes in the regular
> rotation are of varying ages, 8-4 months old, and I have not seen any
> correlation of errors with tape age.
>
> The size of the backup has increased slightly in recent weeks, but not
> dramatically, going from about 16GB to about 18GB.  The drive's
> hardware compression is disabled - Amanda is configured to use
> software compression for better tape usage estimation.
>
> The latest from Dell Tech support was to update the firmware on the
> RAID/SCSI controller, now at rev 2.48.  That does not seem to have
> remedied the problem -we're still getting the same errors.
>
> I would appreciate any hints or tips that anyone can offer.
>
> Nick Barendt
> VXI Technology, Inc.

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