frecover and fbackup

[Dario_1]

Hello Everyone!!!

Is it possible to "break" frecover? A user wanted me to use a tape created on Server1 in January to recover a directory to Server2;
when I went to recover the tape index to find out if that directory even
existed on the tape, I got the following error messages:


/ (root on Server2):frecover -I /tmp/fbackup.011003.index -v -f /dev/rmt/0m
frecover(2105): did not find expected file marker
frecover(5419): checksum on volume header is incorrect.
frecover(5420): not an fbackup volume; magic value is incorrect
frecover(2105): did not find expected file marker
frecover(5412): Do you wish to try to salvage this volume? (^[yY]/^[nN]) y
frecover(5413): attempting to read backup following bad volume header


Thinking perhaps the tape drive on Server1 was the problem, I mounted
the tape in Server3 and was able to recover the index without any errors.

Taking it one step further, I attempted to recover the index from last
night's full backup of Server2 on Server2, and got essentially the same
error messages:


/ (root on Server2):frecover -I /tmp/fbackup.032703.index -v -f /dev/rmt/0m
frecover(2105): did not find expected file marker
frecover(5419): checksum on volume header is incorrect.
frecover(5420): not an fbackup volume; magic value is incorrect
frecover(2105): did not find expected file marker
frecover(5412): Do you wish to try to salvage this volume? (^[yY]/^[nN]) y
frecover(5413): attempting to read backup following bad volume header
/ (root on Griffin):


Attempting to recover the index from that tape onto Server3 works fine, so
the problem seems to be with frecover, not with fbackup.

Thank you for your help.

Dario

[Michael Steele_2 · Accepted solution]

Its looking for an end of record on the tape and since the fbackup was incomplete there is no end of record marker.

Additionally, the tape may not be rewound past any existing records on the tape. Did you simply eject the tape during the fbackup? Do you ordinarily indicate an automatic rewind or a no rewind backup?

/dev/rmt/0m - automatic rewind

/dev/rmt/0mn - no rewind

Try:

mt -t /dev/rmt/0m rew
mt -t /dev/rmt/0m rew
mt -t /dev/rmt/0m rew

...to get all the way back to the start of the tape for sure. And then:

frecover -I /tmp/fbackup.011003.index -v -f /dev/rmt/0m

Also try another known good tape.

[Dario_1]

Hi Frederick:

Thank you for your answer. Here is the script we are executing to run the backup.

/usr/bin/sleep 60
/usr/sbin/sync /usr/sbin/sync /usr/sbin/sync
/usr/bin/sleep 10
/usr/sbin/fbackup -f /dev/rmt/0m -c /var/adm/fbackupfiles/fbackup.config -0ug /v
ar/adm/fbackupfiles/full.graph
/usr/bin/sleep 120
/usr/bin/date
/usr/bin/mt -f /dev/rmt/0mnb offline
/usr/bin/sleep 120
/var/adm/fbackupfiles/oralistnerstart.sh

Regards,

Dario

[John Dvorchak]

One thing that bothers me about the 3rd to the last line in your script:

usr/bin/mt -f /dev/rmt/0mnb offline

uses the "no rewind" device /dev/rmt/0mnb. I am not sure if "mt offline" will force a rewind before ejecting it but it looks to me that it would just eject the tape where ever it is positioned. I would remove the "n" from the device file:

usr/bin/mt -f /dev/rmt/0mb offline

Good luck

[Dario_1]

We'll do. Thank you again.

DR