We have the same problem with  ADSM V2.1.5.15   (Aix4.2)  and IBM support
suggested  to upgrade to 2.1.5.18.

This is the result from today  with 2.1.5.18


NR8340I FILE volume
                          /home/adsm/file_device_class/000083F0.BFS
mounted.
10-07-1998 08:25:11      ANR1101I Migration ended for volume
                          /home/adsm/file_device_class/000083CF.BFS.
10-07-1998 08:32:06      ANR0390W A server database deadlock situation has
been
                          encountered: lock request for transaction
0:1658323352
                          will be denied to resolve the deadlock.
10-07-1998 08:32:06      ANR9999D afbackup.c(1385): Lock acquisition
(xLock) failed
                          for backup optimization.
10-07-1998 08:32:06      ANR1133W Migration terminated for volume
                          /home/adsm/file_device_class/000083CD.BFS -
internal
                          server error detected.


And this normally happens when the server is quite busy:  Client sessions
sending data + Migrations disk to tape.