Deleting storage pools
The system storage pool, the system.log pool, and user storage pools have different deletion requirements.
Deleting the system storage pool is not allowed. You can delete the system storage pool only after you have deleted the file system.
You can delete the system.log pool by deleting all the disks in the system.log pool. You do not need to run a policy to empty the system.log pool first, because the system.log pool can only contain log files, and those are automatically migrated to the System pool when you delete the system.log pool.
In order to delete a user storage pool, you must delete all its disks using the mmdeldisk command. When GPFS deletes the last remaining disk from a user storage pool, the storage pool is also deleted. To delete a storage pool, it must be completely empty. A migration policy along with the mmapplypolicy command could be used to do this.