In my previous post, I created a few fixed volumes for the backup pool in my TSM sandbox. In some scenarios, you may find it is flexible to use the dynamic volumes.
In my TSM sandbox, I will configure the dynamic volumes to use the four 50G drives (G, H, I, J).
1) Update the device class to assign the folders.
update dev FILE directory="G:\deduppool,H:\deduppool,I:\deduppool,J:\deduppool"
2) Update the storage pool to define the max scratch volume numbers (it is up to your disk size).
update stg deduppool MAXSCR=199
3) Start a backup job and check the storage pool usage and volumes. You can see a new volume has been created automatically.
Jackie Chen's IT Workshop 
this is the way i use for the clamation, but you must pay attention to collocation and volume size, otherwise reclamation will be a pain in the ass