Replying to P/DAS-related messages

The operator’s reply to the IGF52xA messages directs the P/DAS action, as described in Table 1. In some cases, the activities performed by P/DAS are based on a combination of the operator reply and the environment at the time that the P/DAS swap request is made.

Table 1. Reply options for IGF52xA messages
Your reply (to message) . . .	Results in this system action . . .	Notes . . .
Terminate Pair, and Swap (IGF520A)	This reply directs the system to perform the following functions: End the PPRC pair and stop copy operations. Other PPRC operations for other pairs continue unchanged. Redirect all application I/O from the source device ssss to the target device tttt. Application I/O is not affected by the device switch. The I/Os only update the secondary volume from this point on, and the primary and secondary volumes will no longer contain the same information.	In a sysplex, issue this reply from the main system only. Application: For device migration scenarios where the source volume is no longer going to be used (such as when the device lease will expire) and you want to change from one set of primary volumes to a second set of primary volumes.
Switch Pair, and Swap (IGF520A)	This reply redirects application I/O to the secondary volume. The system takes action according to the PPRC environment that is in effect at the time of the swap request. The action performed depends on the following two conditions: How the PPRC paths are currently established Whether the target device is the same size as the source device The resulting system actions are summarized in Table 1.	In a sysplex, issue this reply from the main system only. Application: For device or subsystem maintenance, and workload movement.
Continue Swap (IGF520A, IGF521A, or IGF522A)	This reply prompts the system to redirect application I/Os from the primary volume to the secondary volume. Thus, all I/Os that were directed to the source device ssss are now directed to the target device tttt. After completion of this option, device ssss is no longer involved in any operation. Like dual copy, the additional space on the target device tttt cannot be used until an ICKDSF operation has been run against the target device to rebuild the VTOC so the additional volume capacity is recognized.	This reply is valid within sysplex and nonsysplex environments. In a sysplex, issue this reply from any system. Application: To remove a primary volume from the configuration.
Try Again (IGF521A or IGF522A)	This reply directs the system to perform the following functions: End the pair, and return both devices to simplex state. It is the equivalent of issuing a CDELPAIR command for the PPRC pair. Establish a new PPRC pair in the reverse direction. The new path is from the new primary (original secondary volume, device number tttt) to the new secondary (original source volume, device number ssss). This is the equivalent of issuing a CESTPATH and CESTPAIR command for the PPRC pair. Immediately suspend the new PPRC operation. This forces all changes made to the secondary to be recorded in the bit maps for the operation. The changes are not copied to the original primary, device number ssss. This is the equivalent of issuing a CSUSPEND command for the PPRC pair just established. Redirect application I/Os from the primary volume to the secondary volume. Thus, all I/Os that were directed to the source device (ssss) are now directed to the target device (tttt). After completion of this option, device ssss is no longer involved in any operation.	Before this option is used, paths have been established in the opposite direction from the target device’s storage control to the source device’s storage control. In a sysplex, issue this reply from any system.
Terminate Swap (IGF520A, IGF521A, or IGF522A)	This is a request to end the swap operation. Message IGF512I message is issued to the system operator log as follows: `IGF512I SWAP FROM ssss TERMINATED - SWAP TERMINATED BY OPERATOR` P/DAS returns error code 16 to the system.	In a sysplex, issue this reply from any system.