The FlashCopy to PPRC Primary Volume function (Peer-to-Peer Remote Copy) enables you to share Compatible FlashCopy® V2 T-VOLs and TCz P-VOLs. When you share Compatible FlashCopy® V2 T-VOLs and TCz P-VOLs, the status of the TCz pairs must be Duplex, Pending, or Suspend. You can create TCz pairs after creating Compatible FlashCopy® V2 relationships, or create Compatible FlashCopy® V2 relationships after creating TCz pairs.
You can create Compatible FlashCopy® V2 relationships after creating TCz pairs only when the specified options are used in the following host interfaces:
- DFSMSdss: FCTOPPRCPRIMARY
- TSO: TGTPPRIM (YES)
- ICKDSF: TGTOKASPPRCPRIM (YES)
- ANTRQST macro: TGTPPRIM (YES)
For information about using Compatible FlashCopy® V2 with TCz, see Using Compatible FlashCopy® with TrueCopy for Mainframe.
The requirements of the FlashCopy to PPRC Primary Volume function follow:
- TCz is a prerequisite for using the FlashCopy to PPRC Primary Volume function.
- The FlashCopy to PPRC Primary Volume function cannot be used for TCz pairs that are registered in consistency groups.
- Data that Compatible FlashCopy® V2 copies to TCz P-VOLs is transferred to TCz S-VOLs asynchronously. TCz displays the progress of the asynchronous data transfer. Depending on the timing of the Compatible FlashCopy® V2 and TCz copy operations, a time delay might occur and the TCz asynchronous data transfer might progress slowly.
- If the Compatible FlashCopy® V2 S-VOL and T-VOL are Dynamic Provisioning for Mainframe volumes, the number of pages remaining in the T-VOL might differ, depending on the timing.
- If you create
TCz pairs or resynchronize suspended pairs when
Compatible FlashCopy® V2 relationships exist,
Compatible FlashCopy® V2 prepares as many copies as the number of relationships. The higher the number of relationships per volume, the longer it takes for
TCz pairs to become Duplex. Even with less load, it takes approximately 1.5 times longer when the
TCz pairs are not used with
Compatible FlashCopy® V2.
When using the FlashCopy® to PPRC Primary Volume function, the maximum number of relationships (or datasets) per volume should be 2,000. If that is not possible, establish one relationship for each volume. This causes non-data-set parts to be copied as well, but the status of the TCz pairs will change to Duplex in a shorter time.
- The zHyperWrite function and the FlashCopy® to PPRC Primary Volume function can be used together. However, if a Compatible FlashCopy® relationship is established, the writing with zHyperWrite to the target TCz overwrites the Compatible FlashCopy® data. In addition, if a Compatible FlashCopy® relationship is established while the writing with zHyperWrite is in progress, the zHyperWrite data is overwritten by the copy operation with Compatible FlashCopy®.
- The volume copy operation (of which a T-VOL is a TCz P-VOL) might not be performed by using some applications on the host. For details, see Why you use IBM Db2® Cloning Tool for z/OS®.