Thanks for the additional info on that vaulted volume. With an Access state of Offsite, the Move Data should operate on local primary pool volumes containing the same data. Whereas that didn't happen, it calls into question the state of the online volumes or whether the TSM database contains entries for any files on that offsite volume. I'd start by performing a Query CONtent on that volume, and then add DAmaged=Yes, to see if something strange going on there: it's not impossible that the volume % utilization suggests data on the tape but, due to problems, the database has no info for any files on the tape. For completeness, perform queries on the storage pools themselves, to assure no odd state. If a repeat of the Move Data produces the same non-results, attempt on similar volumes to see if there is a more widespread issue, and see if any further Activity Log messages are produced to lend clues. Hopefully, the library is not now returning bizarre indications to the TSM server for volumes in certain locations in the library. You might want to review the TSM Activity Log at restart time, when it would have tested the inventory of the library.
Richard Sims