The only way to reclaim a tape pool with one tape drive is by using disk as file sequential storage pool and setting up a reclamation storage pool. Of course you said you do not have much disk space. So this may not help you.
You can define a reclamation storage pool for the server to use when reclaiming volumes. The purpose of the reclamation storage pool is for temporary storage of reclaimed data. The reclamation storage pool must be a primary sequential storage pool.
Since you have only one tape drive, you can set up a file sequential volumes on disk devices.
tsm> def devclass devclass_name devtype=file directory=/tsm/storage/seq_files maxcapacity=20M
The above example creates a devclass for you to use your random disk with the size of 20 megabytes.
Next, you would need to create your reclamation storage pool.
tsm> def stg reclaimpool devclass_name maxscratch=100
Then define or update the storage pool for the tape drive you want to reclaim.
tsm>update stg tape_pool_name reclaimstgpool=reclaimpool
Finally, update the reclamation storage pool so that data will migrate back to the tape_pool.
tsm> update stgpool reclaimpool nextstgpool=tape_pool
Hope this helps!!
- David Johnson