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- Newsgroups: comp.os.rsts
- Path: sparky!uunet!stanford.edu!agate!doc.ic.ac.uk!syma!stevedc
- From: stevedc@syma.sussex.ac.uk (Stephen Carter)
- Subject: Re: Exabyte Backup Failures
- Message-ID: <1993Jan27.083406.19472@syma.sussex.ac.uk>
- Organization: University of Sussex
- X-Newsreader: Tin 1.1 PL5
- References: <1k4rs4INN5tv@nigel.msen.com>
- Distribution: inet
- Date: Wed, 27 Jan 1993 08:34:06 GMT
- Lines: 77
-
- Dan and Karen Sugalski (dan@msen.com) wrote:
- : Stephen Carter (stevedc@syma.sussex.ac.uk) wrote:
- : : |
- : : ?Error reading Backup set
- : : ?Data error on device
- : : ?Error reading Backup set
- : : ?Data error on device
- : : ?Unexpected error 14 in RSTRMS
- : : |
- :
- :
- : : What is it?
- :
-
- THANKS to dan and karen (?) for her/his/their informative
- reply.
- :
- : What seems to happen is that somewhere between the tape drive and the
- : TMSCP handler, a packet gets lost, and the two get out of sync, never
- : again to talk. (We have to power the drive and computer off--a reboot
- : doesn't seem to be enough)
-
- Rings a BIG bell. Although this precise power off does not
- often happen, 'losing' the exabyte is not unusual. We get it
- back either by a power off of the deck, or a re-boot.
- :
- :
- : You might try upgrading to 10.1 (Skip 10.0 unless you're ready to apply
- : several dozen patches, including one that's not documented anywhere, but
- : is lurking on the upgrade tape). The TMSCP handling is reportedly better.
- : I don't have any experience with the drives on it, though, as I don't
- : know anyone with one of the tape drives that is using it.
-
- Upgrade to 10.1 not an option in real terms. (Mind you
- despite paying mtce, I've not seen a 10.1 tape, nor a Software
- Dispatch for ages... No worries though.
-
- :
- : Alternatively, you may want to try putting a pause of some sort between
- : the BACKUP commands (maybe the big dump of data is causing a probelm and
- : giving the drive a chance to flush buffers and such will help). If you're
- : doing the verify after each backup, then *don't*! Do both backups firtst,
- : then verify the tape.
-
- Um, pause I understand. Backup without verify I understand, but
- how do I verify only?
-
- :
- : Finally, check to see if there are any batch jobs that might be running in
- : a different queue. (The bigger backup may be overlapping something else.)
- : Also consider doing a SET SYSTEM/NOLOGINS in the com file before the
- : backup starts. (You may want to shut down the other queues, as well as any
- : other jobs that may be running)
-
- System usually quiescent (nice word that) - after all it is
- Saturday Night :-). Even if/when other jobs happen to be around
- this makes no difference to the problem.
-
- :
- : And, even more finally, back up the non-system disk *first*. It's been by
- : experience that, once TMSCP loses it, the backup/restore job is immortal.
- : (Looks to have pending async IO--prio/runburst go to 128/127 but doesn't
- : die) $SHUTUP won't be able to bring the system down, so you'll have to
- : power off the machine. Dismount the big drive before you do--one fewer
- : drive to clean...
- :
- Will do.
-
- Will change job anyway to do DU1, DU0, and not to verify.
-
- Thanks again.
-
- (PS. Terry, where were you when I needed you - :-)
-
- Stephen Carter, Systems & Operations Manager, Computing Services,
- University of Sussex, Brighton BN1 9QJ, UK
- JANET : S.Carter@uk.ac.sussex.central
-