We have a number of Version 6 TSM servers running under zSeries Linux.
These were installed with 6.2.2.0 server code and subsequently upgraded
to 6.2.5.0. 

We had 'backup stgpool' processes hang one day last week. The hung
processes had to wait a couple of hours for tape drives to become
available, but did not move any data even when tape drives became
available. The processes were on a library manager client, and
there is a firewall between that TSM server and the library manager.
The TCP connections requesting tape drives for the 'backup stgpool'
processes were severed by the firewall because of inactivity timeouts.

The timeouts should have been prevented by the line:

export LD_PRELOAD=/usr/lib/libkeepalive.so

in the .profile file for the instance user. This line would have
forced the use of a wrapper for the routine that opens TCP
connections. The wrapper would have enabled the transmission of
keep-alive packets over otherwise idle connections. The 'export' was
missing.

Our local documentation for the TSM configuration indicates that the
'export' was originally placed after the lines introduced with the
comment:

# The following three lines have been added by IBM DB2 instance utilities.

Is it possible that the 6.2.5.0 installer removed everything after that
comment (including the 'export') and wrote replacements for the lines
added by the 6.2.2.0 installer, but did not replace the 'export'?

Thomas Denier
Thomas Jefferson University Hospital