Make every effort to minimize power interruptions to PPRC recovery site storage subsystems.
Recommendation: It is recommended that you do not use power sequence control cables between host processors and attached storage controls that contain PPRC secondary volumes. These cables, when installed, allow an attached host processor to remotely remove power from the storage controls. If power sequence control cables are present, ensure that the power-select switches for both clusters are in the LOCAL position. The power-select switches are on an IBM® Storage Control’s power sequence control board. This setting removes the possibility that a processor at the recovery site can inadvertently power down a PPRC recovery storage subsystem.