| Title: | MAGNETIC TAPEDRIVES |
| Moderator: | STKHLM::GJOHNSSON |
| Created: | Mon Sep 21 1987 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 3775 |
| Total number of notes: | 13147 |
Hello, We need urgent help! Our customer is in a desparate situation. Just before closing their financial year they lost all their database. They were running OSF/1 V2.0B on an AS2000 4/200. The file domain containing their usr filesystem and SAP and ORACLE database broke due to a disk error; I had to re-install O/S and SAP. The problem came when we tried to restore database from a TLZ07 tape. (They had made full database backup every day - backup script had always ran OK.) TLZ07 was unable to read any tapes had been written by itself; it produced "Nonrecoverable Hardware Error" with sense key x04, ASC x44, ASQ x80. I tried to read it by other drives, without success. I tried to write some data onto brand new tapes and read it by the broken drive - I got the same error. The other interesting thing is that tape drive was swapped last November; I was unable to read a tape written before that, in October! Now customer's only hope is that we will "do something" on the issue or they will lose one year's work. My questions: - what do these ASC/ASQ figures mean? - is there any place in magtape engineering where tapes could be thoroughly checked to - hopefully - restore data? - I know this is an old and unsupported configuration. Anyway, is there any known problem between OSF/1 V2.0B SCSI driver and TLZ07 that could cause such data corruption on tape? - Any ideas, please?... Thanks in advance, Imre POLGAR MCS Hungary I posted this in DIGITAL_UNIX, too.
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 3658.1 | Compression Fault! | UTRTSC::VISSER | Fri Feb 14 1997 21:39 | 35 | |
I can only give some light on the ASC/ASCQ:
Refer to note 3605.1 for a long list of ASC/ASCQ's.
From that list:
04/44/80 -> Hardware Compression Fault.
Probably there is a severe problem with the drive's
compression-circuit, which causes this problem.
If you get the SAME errors on another TLZ07, the problem was induced
during WRITING.
The symptom you have may be two-fold:
1. Restores fail directly at BOT. It this situation, it MAY be
expected that ALL data is written in a bad way, caused by the
compression chip. There is ONLY ONE way for it to work properly
but VERY MANY ways for it to fail.
I think any form of recovery may be close to impossible.
2. The 04/44/80 appears somewhere DURING restore. This would
indicate that there are 'broken parts of data'. There MIGHT be a
chance, once you would know the 'broken spots' (I do not know
how to mark them with special equipment or software), you might
try to skip over them (e.g. with a SCSI SPACE-BLOCK or
SPACE-FILE). With SPACE-BLOCK you will have a hole in the data
or (if it contains backup-control information) may loose the
whole context of data following.
SPACE-FILE will loose a complete safeset (FILEMARKS are between
savesets or backup-sets).
Perhaps there is somebody around with more knowledge, who can make a
better estimate.
Jan
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| 3658.2 | BPSOF::POLGAR | Fri Feb 21 1997 10:09 | 9 | ||
Jan, Thanks for your reply! It seems that we will be able to restore most of data skipping over bad records. Now the question is how the customer will be able to unpack it. Regards, Imre POLGAR | |||||