Topic: flexbackup - potential failed backup

[Steve Bush]

I have come into a situation with Flexbackup that potentially cause failed backups.
The disk usage on my server outpaced my DLT1 tape drive.
I believe my tape drive hit the end of the tape and initiated a rewind, it then continued to backup from the begining of the tape overwriting the first part of the backup.

The only tell tale sign was in the flexbackup log, which I just noticed.
I would normally see:
At block 558826.
|------------------------------------------------
| File number 2, index key 200305280200.15


The day we ran out of tape space, I saw:
At block 23.
|------------------------------------------------
| File number 2, index key 200305290200.13
| Backup of: /boot

[Steve Bush]

FYI - This is SME5.6

[Tim Jones]

I'm not sure which kernel is provided within 6.0, but the 2.4 kernels (since 2.4.9) have had a problem where the kernel does not recognize end of tape properly.  Kai Makisara (the st driver author) has a patch for the 2.4.20 kernel, and the patch is in the 2.4.22 kernel.

You can read more about the problem and download Kai's patch from:

http://www.kolumbus.fi/kai.makisara/st-eot.html

I don't know if this will resolve your FlexBackup problem, but the missed EOT affects all backup applications that use the native st drivers (tar, cpio, bru, afio, etc.).

Tim

[Steve Bush]

Thank you for responding.  I've forwarded this thread to smebugs.
I'm grateful that I didn't find this out by needing to do a full restore.
For now, I'm archiving off data from my server and will be watching the disk space carefully.

[Kelvin]

Hi Steve,

Have you tried Shad Lord's Arkeia backup contrib ? I have had tapes (not DLTs though) run to the end and Arkeia asks for a new tape instead of just rewinding and overwriting the beginning of the tape.

Just a suggestion.

Kelvin

[Steve Bush]

Thanks for the suggestion.
I like keeping things as stock as possible, so we just cleaned up the server so that the backup fits on one tape.  I'll watch the logs a bit more carefully from now on, testing the backup as well.

[Dan Williams]

Hi Steve,
Just curious, have you tried restoring files from flexbackup?
What were your findings for success/speed?
I look after many servers, and buyt the Seagate drives bundled with tapeware and hoave great success with this, very nice reports, and very quick restores.
I delete files, and do restores monthly to assure it works.
Dan

[Steve Bush]

I didn't have problems with flexbackup, until this end of tape bug showed up.  It takes a bit longer to restore single files than my Win2k servers running Backup Exec, and it isn't as user friendly, but up to now its always worked.  I don't want to think what would have happened if I hadn't tried to restore a file and found out all my backups were bad. Can you imagine trying to restore from a drive failure...I'd be looking for another line of work!!!   To me that is the #1 job of IT...make sure the data is backed up.  Anyway, I hope everyone is reading this thread so they begin checking their backups frequently.

[Hugo]

Hello folks,

Having finished (?) my 5.6 server instalation with sp6 I wanted to test if the (flex)backup is valid. I deleted some files and took a tape with a scheduled backup from the day before.
I started a restore from the server-managers advanced tape manager and left my office after starting  the restore. This morning I had a HUGE surprise!!
The flexbackup.extract.log had taken up ALL of my servers hd space remaining!
Of course I rmed thge file but I still have no idea what went wrong;
Any ideas?
TIA
Hugo

[Hugo]

Hello folks,

Having finished (?) my 5.6 server instalation with sp6 I wanted to test if the (flex)backup is valid. I deleted some files and took a tape with a scheduled backup from the day before.
I started a restore from the server-managers advanced tape manager and left my office after starting  the restore. This morning I had a HUGE surprise!!
The flexbackup.extract.log had taken up ALL of my servers hd space remaining!
Of course I rmed thge file but I still have no idea what went wrong;
Any ideas?
TIA
Hugo