The ability to move processor power dynamically becomes important when you need to adjust to changing workloads.
Processors have minimum and maximum values associated with them. These values enable you to establish a range within which you can dynamically move the resource without needing to restart the logical partition. Minimum values dictate what is required to restart the partition. A minimum value of zero is valid. A partition with zero processors or processing units is not functional. For example, a test partition can free up valuable processing power to apply to a production partition if needed. Once the demand on the production partition is over, the processing power can be moved back to the test partition.
For both shared and dedicated processors you can specify a minimum value equal to the minimum amount of processing power needed to support the logical partition. The maximum value cannot be more than or equal to the amount of processing power available on the system. If you change either the minimum or maximum value, it will require you to restart the entire partition. If the minimum value is not met for all logical partitions, only the primary will restart.
Note for Partitions Not Using DB2 UDB Symmetric Multiprocessing (SMP): Changing processor resources dynamically does not affect the number of tasks used to rebuild database access paths. To apply the processor resource change to database access paths, you need to restart the partition. If you have SMP enabled, no restart is required.