Figure 1 shows what the configuration looks like after the P/DAS function has completed. I/O has been redirected to the volume that was originally the secondary of the PPRC pair. Application I/O continues without interruption. In the example shown in Figure 1, the operator has chosen to keep both of the PPRC pair devices in operation. You can reverse PPRC operations if you have established paths in both directions.
Figure 1. P/DAS swap operation complete. Disk
device 581 is now the PPRC primary volume, receiving updates from
attached systems through a network of ESCON Directors.
PPRC copies all updates to device 191, which has now become the secondary
volume.