I came across an interesting anomaly when restoring the 5.1 TSM Database
when an external library manager is implemented.

With 5.1 TSM, external libraries are supported using DEFINE PATH.
Well, the result of DEFINE PATH does NOT put EXTERNALMANAGER=blah in the
devconfig file.

What this means is that if you NEED to restore your 5.1 TSM database, you
must manually edit the devconfig file and add the EXTERNALMANAGER=blah
parameter to the DEFINE PATH.

After doing such, my database restore worked normally.

FYI

Tom Fought
OCLC, Inc.