By extension, a logical question: Has Expiration been running? (In a neglected TSM server, it might not be, and getting that going could free a bunch of space.) If Expiration has been running, a recourse is to go looking for obsolete nodes and filespaces to dispose of.
If your system has USB, you could conceivably plug in some inexpensive random access media to constitute a temporary storage pool to be able to initiate reclamation. NFS mounting is another way to get space. Richard Sims