Provided are a method, system, and program for managing storage units. Storage
pool information indicates an assignment of a plurality of storage units to a plurality
of storage pools, wherein each pool is assigned zero or more storage units, and
wherein data associated with one storage pool is stored in at least one storage
unit assigned to the storage pool. User selection is received to move at least
one storage unit to a target storage pool. A determination is made of at least
one storage unit assigned to a source storage pool to move to the target storage
pool. The storage pool information is updated to indicate the determined at least
one selected storage unit as assigned to the target storage pool.