FlashCopy to PPRC primary
This FlashCopy® option allows you to establish a source and target relationship in which the FlashCopy target is the primary device in a PPRC pair. In this way you can create a point-in-time copy and the make a copy of that point-in-time copy at a remote site.
A basic FlashCopy to PPRC Primary configuration, illustrated in Figure 1, is set up as follows:
- Establish a PPRC pair from the local (Volume B) to the remote site (Volume C) and allow the pair to reach full duplex state
- When you want to make a point-in-time copy of volume A, establish a FlashCopy relationship with volume B (the PPRC primary) as the target, specifying MODE(COPY) and TGTPPRIM(YES). When the FlashCopy is requested, the state of the PPRC pair is changed from DUPLEX to PENDING.
- When the background copy on volume B is complete, the FlashCopy relationship is ended, unless INCREMENTAL(YES) was specified. Resynchronization of the PPRC pair begins.
- When the PPRC pair is resynchronized, the state returns to DUPLEX and the point-in-time copy is available at volume C.
The PPRC pair may be synchronous or extended distance. When PPRC-XD is used, you must ensure that the pair is synchronized before using the point-in-time copy at the remote site. If the PPRC primary is being updated, then the pair may be continually out of sync and a quiesce of write operations may be required to ensure that the remote copy is reliable.
When the FlashCopy is initiated, the PPRC pair may be in full duplex state, pending state, or suspended state. If the PPRC pair is in suspended state, then it must be resynchronized in order to obtain the remote point-in-time copy.
The FlashCopy relationship can specify a full volume or extents. When extents are specified, multiple source volumes may be copied to the PPRC primary as long as their extents do not overlap on the FlashCopy target.
The FlashCopy to PPRC Primary option can be used with the INCREMENTAL option. This results in the PPRC primary using incremental updates to resynchronize with the PPRC secondary.