Greetings !
Some of you may remember my last question on backup devices ...
We have a DEC 3000/500 (running 4.0F) with a TLZ06 DAT drive
in its BA35x box (also containing six disks),
and a DEC 2100A 5/250 (4.0D) with an internal TLZ07 DAT drive.
The machines are old. We do local backups (using
dump -0 -u -b 64 -f /dev/nrmt0h /mount-point
) on 60m and 90m DAT tapes.
I used a cleaning tape on both drives before the backup.
When I took the set generated on the TLZ06 drive ('nrmt0h')
and tried proof-reading on the TLZ07, I had several failures
some way into the data. (I did
restore -t -N -f /dev/nrmt0h
dd if=/dev/nrmt0h of=/dev/null bs=64k
to skip over the data part of the 'dump' file. The read errors
were in the 'dd' part.)
It seems the 60m tapes could be read, but not the 90m tapes.
However, they read o.k. on the TLZ06 they were written on.
In the archives, I found a summary by James Anderson of June 1997
where he mentioned that only the TLZ07 can handle 120m tapes.
I took that to mean they can both read and write 60m and 90m
tapes, and I found no hint on incompatibilities with these.
So I ask:
1) Should 60m and 90m tapes be exchangeable between TLZ06 and TLZ07 ?
Only uncompressed, or also compressed ?
2) If yes: Are these read errors an indication of wear,
of misalignment, or are there any other guesses ?
3) Should the error log (which one ?) contain information for more
exact diagnostics, and would you consider it worth the effort
to analyze that - or is DAT technology simply to be discarded ?
TIA,
Joerg Bruehe
--
Joerg Bruehe, SQL Datenbanksysteme GmbH, Berlin, Germany
(speaking only for himself)
mailto: joerg_at_sql.de
Received on Fri Feb 18 2000 - 17:08:27 NZDT