Topic: Flexbackup Restore Problems

[Boris Mann]

OK, it seems like many people are having similar issues with restoring backups. Nobody seems to have a final solution, though.

Here is the situation (SME 5.5.x):
- nightly backups being performed with flexbackup
- all logs show successful completeion of backups

- trying to restore a particular set of files, have used all the correct scripts, I keep getting a variety of errors from either gzip or something else

- if I try "flexbackup -list", I get an error
- if I try it a second time, I get an error
- on the third time, it completes successfully, and I "see" the files I am trying to restore (I assume this is the tape moving forward to the correct starting point...)

- whatever I do with extract, it finally ends, telling me the files could not be found

Lastly, I started experimenting with dd. I got a file off the tape using:
  dd if=/dev/nst0 bs=10k of=extract.tgz

I actually wasn't sure what type of file "dd" spits out, so I just named it ending with .tgz

If anyone has ideas on how to get flexbackup working correctly OR what to do with a file retrieved by dd, it would be much appreciated.

Thanks,

-- Boris Mann

[Kelvin]

Hi Boris,

If you use flexbackup for backups, I recommend you add Darrell May's Advanced Backup / Restore server manager panel. It makes it easier to perform ad-hoc backups as well as simplyfies restores.

By the way, since you use flexbackup for your backups, could you have a look at my post at :-

http://forums.contribs.org/index.php?topic=17612.msg68690#msg68690

and post your comments ?

Cheers,

Kelvin

[Boris Mann]

> If you use flexbackup for backups, I recommend you add
> Darrell May's Advanced Backup / Restore server manager panel.
> It makes it easier to perform ad-hoc backups as well as
> simplyfies restores.

Thanks, Kelvin. I had already been using the panel and tried to restore with it first...it failed as well. By saying "used all the correct scripts", I should have been more specific -- there are various answers here about doing the following --

  mt -f /dev/nst0 rewind
  mt -f /dev/nst0 fsf 1
  flexbackup -extract -files extract-files
  mt -f /dev/nst0 rewind

All failing, some with gzip errors, sometimes with /dev/tty not found errors, etc.

[Kelvin]

Boris,

What tape drive are you using and what interface is it on ?

Kelvin

[Ed Form]

Boris Mann wrote:
>
> OK, it seems like many people are having similar issues with
> restoring backups. Nobody seems to have a final solution,
> though.
>
> Here is the situation (SME 5.5.x):
> - nightly backups being performed with flexbackup
> - all logs show successful completeion of backups
>
> - trying to restore a particular set of files, have used all
> the correct scripts, I keep getting a variety of errors from
> either gzip or something else
>
> - if I try "flexbackup -list", I get an error
> - if I try it a second time, I get an error
> - on the third time, it completes successfully, and I "see"
> the files I am trying to restore (I assume this is the tape
> moving forward to the correct starting point...)
>
> - whatever I do with extract, it finally ends, telling me the
> files could not be found...  SNIP

This sounds very like a restore problem I found in 5.6. I took the same tape to a fully updated machine and could restore perfectly. Updated the machine which wouldn't restore and it was fine frfom then on.

I suggest that yoy take the tape to a machine running a different iteration of SME and see whether it can be read.

Ed Form

[Boris Mann]

OK, more info.

Kelvin: I don't have the drive in front of me. It's an IDE tape drive. I now have a Sony SDT-5000 with an Adaptec SCSI card that I am trying the tapes with.

Ed: I had seen your previous post about switching to a more upgraded version. I got the tapes delivered to me and stuck them in a 5.6update4 box here...and same errors.

I have now tried an interactive restore, using "flexbackup -restore". I could successfully cd to the correct directory, and used "add" to add the two files I wanted. I then issued the "extract" command, which seemed to run for a long time.

Here are the errors:
buffer (reader): failed to read input: input/output error

gzip: stdin: unexpected end of file



Bunch of other stuff, the only part that looks interesting saying:
End-of-tape encountered

Next thing I'm trying is dd to grab everything off the tape, using:
dd bs=10k if=/dev/nst0 of=extracted.gz

Which gives me the following error:
dd: reading '/dev/nst0': input/output error
43052+0 records in
43052+0 records out

I tried gzip -d on the file, but I get a very familiar "unexpected end of file" error.

So, how about extracting the files by num? Sounds great:
mt -f /dev/nst0 rewind
mt -f /dev/nst0 fsf 1
flexbackup -extract -num 725868 (got the number from a previous -list command)

Output of this command at end of msg.

Now I'm stumped. Is my tape corrupted? Why can I list everything but not extract!? Any suggestions are much appreciated...must get some rest...

-- Boris

|------------------------------------------------
| Positioning tape at file number 735868
/dev/nst0: Input/output error
|------------------------------------------------
At block 43054.
|------------------------------------------------
| buffer -m 3m -s 10k -u 100 -t -p 75 -B -i /dev/nst0 | gzip -dq | restore -x \
|  -o -v -b 10 -f -
|------------------------------------------------
buffer (reader): failed to read input: Input/output error
buffer (reader): internal error, failed to remove semaphore: Invalid argument

gzip: stdin: unexpected end of file
restore: Tape read error on first record
Verify tape and initialize maps
Input is from file/pipe
|------------------------------------------------
At block 43054.
|------------------------------------------------

[Kelvin]

Boris,

I take it the SDT-5000 is a DAT drive (sorry, not familiar with the model) ? You have to be careful about moving tapes between drives. I found out the hard way years back that you cannot always move dat tapes between different drives. If the drives are from the same manufacturer, maybe, but between manufacturers, be careful. I once had a Seagate DAT drive die and bought a Sony DAT of the same capacity to replace it. However, it refuses to restore from the tapes (can see the catalog but cannot restore). An quick phone call to Seagate was followed by a reply to confirm what we already suspected. The format used by the drive hardware to write to the tape is different (even though we are using the same software - NT backup) between the makes and therefore, the only way to restore the tape was to get another Seagate DAT drive (or one of the rebranded ones of the same make).

>Now I'm stumped. Is my tape corrupted? Why can I list everything but not
>extract!?

Sounds just like the problem with the NT Backup I had years before.

The errors you are getting may be a result of the incompatible drive formats, a corrupted tape or that the backup reached the end of the tape before completing.

Sorry, can't be more specific.

Kelvin