Blockset sorting performance may be improved by using the Cache Fast Write (CFW) capability of IBM's storage controllers. Because IBM's latest storage subsystems have large cache sizes and high speed disk arrays, the use of CFW may not produce a significant performance gain.

The CFW parameter specifies whether DFSORT can use CFW when processing SORTWKdd data sets. The default is CFW=YES.

If you use the Hyperswap function in an environment that has a high availability configuration, you should specify CFW=NO to prevent DFSORT from abending when a Hyperswap is initiated.