What matters is what kind of disk storage pool it is. It is either:
DEVCLASS=DISK (random access disk space)
DEVTYPE=FILE (sequential access disk files; DEVCLASS will be a name of your choosing)
There has been debate for years about which is better; we aren't going to argue that here. We use both.
If it's DISK, reclamation is not involved. Data moves out via migration, and then it's gone. Once it's really empty, you can Q VOL to see the files that make up the stgpool, then DELETE VOL for each. If it's not really empty, DELETE VOL will fail; use MOVE DATA to empty it. Once all TSM volumes are deleted, you can reuse the space for other uses. DELETE STGPOOL can be good housekeeping, but it is not necessary.
If it's FILE, you need to reclaim each file (aka volume). If you set it up for allocating from scratch, then reclamation (or MOVE DATA) will delete each file (volume) as it is emptied, after the reuse delay. If it's set up for permanent allocation, then you can DELETE VOL once it shows as empty. The space can be reused once you use UPDATE DEVCLASS to leave out the directories you want to repurpose, while leaving in the others you want to keep using. It is OK to UPDATE DEVCLASS before you reclaim or DELETE VOL, which will prevent any new allocations in the space you want to empty, as you work.
