http://www-01.ibm.com/support/docview.wss?uid=swg22004973

Starting with Spectrum Protect v8.1

How can the container sizes of directory container stgpools be reduced if the amount of data held in that stgpool decreases significantly ?

When the amount of data stored in a directory container stgpool decreases, the size of the containers is not reduced accordingly. The exception are fringe cases where a defragmentation process is started to recover space from a container.

This works as designed.

The following procedure can be used to reduce the container sizes using the special server option NOMOVEPREALLOC which is currently not documented in the Knowledge Center:

*** Note: You should use this process when there is very little activity on the server.

1) Verify the current container configuration with:

tsm> q container stg=deduppool f=d

2) Run the following TSM server command:

tsm> SETOPT NOMOVEPREALLOC YES

During a MOVE CONTAINER process the server can then allocate space in new containers based on the used space in the source containers rather than pre-allocate space based on the size of the source container files.

3) Ensure you have free space available at the OS level in the directory for the new condensed containers. The free space should amount to the size of the source container you want to condense.

4) Issue the MOVE CONTAINER command (see the link below) for one container you choose.
Ex:

move container /data1/storage/dir1/00/0000000000000001.dcf stgpooldir=/data/storage/dir2

5) Wait for the running MOVE CONTAINER process to finish. If all containers you intend to condense have been dealt with, go to step 5. To condense another container go to step 2.

6) After all chosen containers have been processed, run the TSM server commands:

tsm> RESET CONTAINERSIZE DEDUPPOOL
tsm> SETOPT NOMOVEPREALLOC NO

7) Verify the new container configuration with:

tsm> q container stg=deduppool f=d