Restore failure

[O'lnes]

I use fbackup to backup files , it seems no error, then use the same drive to frecover the file, but it pop up the below error
" unable to read the volume header " , why this happen?
can the files be recoverd? Thank you very much.

[RAC_1]

What command you are using for backup.
give complete syntax.(for frecover also)

[Rodney Hills · Accepted solution]

Either you
- used a tape that did not have fbackup data on it
- or the tape itself went bad
- or the tape drive itself went bad.

Try cleaning the tape drive first.

Try doing some simple fbackup/frecover on the drive with a new tape to determine if it is the drive.

Double check your backup processes. Many administrators have developed scripts to do their backuping and don't find until a month later when they want to restore, that the script was in error and failing.

Good Luck

-- Rod Hills

[Cheryl Griffin]

In addition, what type of tape drive and what is the firmware?

Test the tape drive works outside of fbackup:
# dd if=/dev/rmt/0m of=/dev/null bs=1 count=1

Does this command succeed or fail?
A failure would look like:
dd read error: I/O error
0+0 records in
0+0 records out

Check /var/adm/syslog/syslog.log, dmesg and STM (Diagnostics) for any other errors which might indicate a problem with the tape drive.

Cheryl

[O'lnes]

my command is :
fbackup -v -n -f -I -c
frecover is using `sam'

[Rodney Hills]

I don't see either "-i" or "-g" to specify which files to backup.

Following "-f" should be the device you are backing up to.

Can you look at the log of output generated by "fbackup"? You may want to see if their were any problems.

-- Rod Hills

[O'lnes]

I omit the statement

It is `frecover fbackup -v -n -f /dev/rmt/0m -i /etc/backup.file -c -g /etc/backuplist.txt` , I make sure the statement is no problem cos I use for long time, how can I recover the files without read the volume header? Thank you very much.

[O'lnes]

The full error message when i `frecover` file is as below, how can i recover the files? can i frecover files without read the volume header?

frecover(5409): unable to read volume header
frecover(5418): not an fbackup volume; unable to read volume header
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
frecover(5426): read error while attempting to read index. Skipping.
frecover(5401): Volume 1 completed.
frecover(5404): Press return when the next volume is ready on
/dev/rmt/c4t0d0BES

[Bill Hassell]

Since there was no I/O error listed from frecover, the message means that the tape was never recorded by frecover. You can try to lost the contents with tar (tar tvf /dev/rmt/0m) or cpio, but the error indicates that there is no fbackup on the tape at all.

Now it's possible that someone started to write on the tape after fbackup was finished. It's imperative that any backup procedure popout the tape once it's finished. It's just too easy to write on whatever tape is in the drive...and it was your backup.

[O'lnes]

does it mean the tape can't be recovered?

[Patrick Wallek]

That's what it appears.

Are you ABSOLUTELY SURE that your fbackup is working correctly? I would check your logs VERY CLOSELY as you may have problems with your backup.

[O'lnes]

I can't find any strange error message in the backup log, Can check how can I recover the files?
Thanks.

[Rodney Hills]

If you tested the tape drive and it is functioning correctly, I think it safe to say that the tape is unreadable by frecover.

Therefore I'm sorry to say I don't think the data (if it existed) is recoverable.

-- Rod Hills

[D Waghorn]

We have the same problem, were the header file is not written correctly to the tape. A warning appears and the files are written to tape. The logs then says completed with warnings.

The backup is restorable as we have tried it. For some reason the Label / Header is not been written correctly.