You can establish Compatible FlashCopy® V2 volume relationships using the following host interfaces to the storage system:
- PPRC TSO
- DFSMSdss
- ICKDSF
- ANTRQST macro
- z/VM CP
Data Copy Timing Differences
The timing of data copying differs between Compatible FlashCopy® V2 and IBM® FlashCopy®:
IBM® FlashCopy®: Data is copied when written to the source or target volume.
Compatible FlashCopy® V2: Data is copied when the relationship is established.
Target Volume Considerations
When a relationship is established, the target volume is overwritten with the source volume's contents. Cached data can persist on the host and must be deleted before establishing the relationship, especially when using Reverse Restore or Restore.
To prevent cached data from remaining:
- Unmount the target volume before establishing the relationship.
- If sharing with TCz or URz, ensure data is copied to the S-VOL before deleting cache, stopping I/Os, or unmounting.
Performance Considerations
Establishing more than 100 relationships simultaneously may cause timeouts. To avoid this:
- Divide tasks into smaller groups.
- Establish relationships at intervals of approximately 5 seconds per 100 relationships.