RE: IBM System Storage TS3100 Tape library; unnecessary tape verification by restoring object?

We don't perform a restore verification step after our backups-- we trust the tape management messages to indicate any errors.

We do perform a Display Tape on some tapes...

But we do regularly restore data from our backup tapes-- programmers need test data; we need to investigate why a transaction failed. So we are routinely bringing tapes back from off-site and restoring 'random' files from our daily and monthly backups. So we're reasonably certain that our backup tapes really can be used to restore data.

Plus, we have a contract for a disaster-recovery site, and we perform an annual test to rebuild our primary system on bare hardware. We usually grab a recent set of month-end backup tapes for the test. It's just another test to show that we can actually read data off of our tapes.


It's like the saying about submarines: "A submarine dive isn't successful until the boat returns to the surface!"


Paul E Musselman
PaulMmn@xxxxxxxxxxxxxxxxxxxx


-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of elehti@xxxxxxxxxxxxxxxxxx
Sent: Monday, November 14, 2011 3:21 PM
To: midrange-l@xxxxxxxxxxxx
Subject: IBM System Storage TS3100 Tape library; unnecessary tape verification by restoring object?

Am I doing some unnecessary, over-the-top tape verification with our IBM
System Storage TS3100 tape library?
Are steps 5 and 6 actually needed so as to confirm that the tapes are
readable and that data can be restored from them?
Does the TS3100 tape unit have more than adequate verification
algorithms in it that confirm that the data on tape is readable and
restorable?


Step 1: GO BACKUP and save most user libraries and other objects to the
LTO4 tapes.
Step 2: Seven libraries get saved with these parms. E.g.
SAVLIB LIB(CRMSAT) DEV(TAP01) ENDOPT(*LEAVE) +
SAVACT(*SYNCLIB) SAVACTWAIT(360) +
SAVACTMSGQ(QSYSOPR) ACCPTH(*YES)

Step 3: Save some of the IFS folders: e.g.
SAV DEV('/QSYS.LIB/TAP01.DEVD') OBJ(('/WWW')) OUTPUT(*PRINT)


Step 4: Rewind and DSPTAP
Step 5: DLTF a file from library VERIFYBKUP and get ready to restore
this file from tape
Step 6: RSTOBJ from tape the file that step 5 deleted.

Step 7: CHKTAP DEV(TAP01) ENDOPT(*UNLOAD) to unload this tape and
mount next tape for tomorrow