Bob
I agree with your comments about throwing the tape away. However, can we
assume this scenario:

Full Backup Friday of critical Server. Completed all ok, but during the job
a status appeared (Media Write Error, or Media Position Error) although only
once.

Sunday Server Dies

Come in Monday, and you can ONLY restore from Fridays Backup! Are you
telling me that its VERY unlikely Netbackup will restore ANY Data from the
tapes it used?

Regards

Simon Weaver
3rd Line Technical Support
Windows Domain Administrator 

EADS Astrium Limited, B32AA IM (DCS)
Anchorage Road, Portsmouth, PO3 5PU

Email: Simon.Weaver AT Astrium-eads DOT net



-----Original Message-----
From: bob944 [mailto:bob944 AT attglobal DOT net] 
Sent: 04 May 2006 04:18
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] Re: Help! All Tapes From Scratch Gone - All jobs
failed :(


> I have had this happen to me on multiple occasions. I have had no good 
> explanation for this NBU behavior from Symantec/VERITAS. My

Jeez, how hard is it to key in "frozen media" at support.veritas.com? And
the first one listed is... ta-da!... "How to troubleshoot frozen media on
Unix and Windows."  Just tryin' to help.  :-)

> best guess:
> NBU is unable to verify status or information from the robot for what 
> ever the reason may be. Due to the lack of information it chooses to 
> freeze the available media until an admin sorts things out

It's not "lack of information," it's "errors."  NetBackup tried to use the
tape and a Bad Thing caused the operation to *fail*.  I'd suggest
troubleshooting the Bad Thing.

> I have a script that executes early in the morning daily to try and 
> unfreeze all frozen media because I have lost multiple backups due to 
> this problem. There are many reasons for frozen media. I choose not to 
> investigate unless a media id shows up on the script output more than 
> once.

Amazing.  So, in your environment, it's considered more cost-effective to
risk losing data or fail another backup than to throw out a $50 tape? Sorry,
that's a rude way to put it but it definitely seems like our levels of risk
tolerance in the "no do-overs" disaster-recovery world are different.

IF everything has been running normally
   IF a tape failed last night in three drives
      THEN duplicate any data already on the tape
           throw the freakin' tape away
   ELSE
   IF a drive is down because three tapes failed using it
      THEN fix the drive
           up the drive
   ELSE
   IF a boatload of your tapes are frozen
      THEN put the tapes in right-side up
           turn off the write-protect tab
           back out yesterday's configuration change
           fix your fibre or SCSI
      IOW, your OS, drives or media are broken or misconfigured--
           fix the root cause so this never happens again

Here's my really easy rule:  on the first occurrence of a media error, I
toss the tape.  I think my time and my data are worth it.

Personally, I can't imagine being in a recovery scenario--whether it's a
user file or a full DR scenario--and saying "Hey, it took five tries to get
past that write error, but I finally got the backup to finish; beats me why
I can't restore it.  Must be stupid NetBackup's fault."


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