Cache fast write and sort programs

Ensure that cache fast write (CFW) is off for source volumes that are involved in swap migration, if possible.

A swap migration can be stopped with the GTD2363I message, which informs that Cache Fast Write (CFW) activity is detected on the source volume. This scenario occurs if the target volume is not part of the same DASD subsystem as the source volume. The accompanying GTD2596I message identifies the responsible job name. Most often, a sort program causes the CFW activity. However, other applications can use CFW.

To circumvent this situation, a number of options are available:

• Turn off the CFW feature at the DASD subsystem level. Not all subsystems have the facility to do this action. For more information, see the hardware manufacturer's documentation.
• For sort work data sets allocated on work volumes in a DFSMS environment, the volume can be set to a status of DISNEW (Disable new allocations). For more information, see DFSMS.
• Some applications that use CFW have a facility for turning off the option.
  Note: Point-In-Time migrations are not stopped if CFW activity is detected. All CFW data is committed to the source volume by TDMF before it is copied to the target.