[ADSM-L] ANR8503E after hours of backing up DB2

Hi Folks.

I am running TSM 6.2.1.1 under AIX 6.1.5.  I am writing data to a Data
Domain DD880 using NFS.

We have a long running DB2 backup that backs up about 7TB.  By the
way, this is a fairly new setup.  Most things are fine, but sometimes
I get:

DATE_TIME: 2010-10-06 11:32:11.000000
  MESSAGE: ANR8503E A failure occurred in writing to volume
/tsmstg/cabdd01/tsmcabu/stgfile/dir2/000002CF.BFS. (SESSION: 163)

DATE_TIME: 2010-10-06 11:32:11.000000
  MESSAGE: ANR1411W Access mode for volume
/tsmstg/cabdd01/tsmcabu/stgfile/dir2/000002CF.BFS now set to
"read-only" due to write error. (SESSION: 163)

DATE_TIME: 2010-10-06 11:32:12.000000
  MESSAGE: ANR0523W Transaction failed for session 163 for node
UPBCCLND02 (DB2/AIX64) - error on output storage device. (SESSION:
163)

So far, the Data Domain people say everything is fine, and I can't
find anything relevant in any logs.

#1) How would you guys debug this

#2) It seems to me that TSM should mount another volume if it gets a
write error.  Is there something I am missing to get it to do that?  I
hate dumping hours of backup that apparently DB2 uses 1 transaction
for.

Thanks for any information that you can provide.

--
Andy Carlson
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