I would try reducing your Migration Processes count from the present
4 to 1, as a measure toward problem isolation. Further, try to run
the migration when there are no other processes or sessions updating
the database. I would additionally perform a Query CONtent on the
source volume(s) with DAmaged=Yes, to see if there is that kind of
complication in the storage pool.

Beyond that, I would research back in the Activity Log seeking some
advent of this problem, or indication of something gone awry which
may have precipitated the current problems.  If there had been a
server crash, you may have db damage, depending upon what your db
volume settings are.  TSM Support can possibly guide corrective db
actions, but be prepared for the worst: db restoral to days past.

   Richard Sims