FCINCREMENTAL


>>-+----------------------------------------------------+------><
   '-+-------------------+--+-------------------------+-'   
     +-FCINCRemental-----+  +-FCINCRVERIFY(REVERSE)---+     
     +-FCINCREMENTALLAST-+  +-FCINCRVFY(RV)-----------+     
     '-FCINCRLAST--------'  +-FCINCRVERIFY(NOREVERSE)-+     
                            '-FCINCRVFY(NV)-----------'

FCINCREMENTAL specifies that DFSMSdss establishes a full volume Incremental FlashCopy® relationship from the specified source volume (in the INDD/INDYNAM keyword) to the specified target volume (in the OUTDD/OUTDYNAM keyword). The full volume FlashCopy relationship remains in effect after the initial copy has completed and subsequent changes to the source and target volumes are tracked so that a future FlashCopy operation is performed to only copy incremental changes.

When FCINCREMENTAL is specified and no Incremental FlashCopy relationship currently exists between the volume pair, the storage subsystem initiates background copy of the entire source volume to the target volume.

When FCINCREMENTAL is specified and an Incremental FlashCopy relationship already exists between the volume pair, the storage subsystem only copies the changed data in the specified direction which can be the same as the existing (original) or the reverse of the existing FlashCopy direction. When no updates have been made to the existing target since the last Incremental FlashCopy, the reverse of FlashCopy direction can be used to restore the original source volume back to the previous point-in-time copy state. The new source volume is designated by the INDD/INDYNAM keyword and the new target is designated by the OUTDD/OUTDYNAM keyword on the copy command.

Attention: DFSMSdss does not inhibit writes to the FlashCopy source or target volumes. If you plan to use the Incremental FlashCopy target volume as a backup, you must ensure that the target volume is not updated inadvertently.

Note:

Do not specify the FCINCREMENTAL keyword with any of the following keywords:
- DATASET
- FCINCRMENTALLAST
- CONCURRENT(ANYPREF | ANYREQ | CACHEPREF | CACHEREQ | VIRTUALPREF | VIRTUALREQ)
- FASTREPLICATION(PREFERRED | NONE)
- FCNOCOPY
- FCNOCOPYTOCOPY
Incremental FlashCopy is supported at a volume level. It is not supported for data set FlashCopy.
Incremental FlashCopy relationship is limited to one full volume relationship per volume. However, an Incremental FlashCopy relationship can coexist with other non-incremental relationships.
When you specify FCINCREMENTAL with TRACKS, you must also specify the CPVOLUME keyword. FCINCREMENTAL is supported with the TRACKS keyword only for full volume copy of VM-format volumes with OS-compatible VTOCs.
The benefit of Incremental FlashCopy is to minimize the amount of data transfer needed when a FlashCopy pair is refreshed. There is no saving in data transfer when the no-background copy option is chosen. Therefore, DFSMSdss does not allow FCINCREMENTAL and FCNOCOPY to be specified together.
When you specify DUMPCONDITIONING with FCINCREMENTAL, the volume serial number of the target volume does not change, and the target volume remains online after the copy. A subsequent incremental copy can be made without additional procedure.
When you specify COPYVOLID with FCINCREMENTAL, the volume serial number of the target volume is changed to match the source's and the target volume is varied offline. Prior to performing a subsequent incremental copy using DFSMSdss, the offline volume's volume serial number must be changed by using a utility such as ICKDSF and the volume must be varied online. Although you can specify FCINCREMENTAL with COPYVOLID, IBM® recommends you use FCINCREMENTAL with DUMPCONDITIONING.
The PURGE keyword may be required on subsequent incremental copies.
When FCINCREMENTAL is specified, it requires that the storage facility has the Change Recording feature enabled. The Incremental FlashCopy request fails if the storage facility does not support Change Recording.
The Incremental FlashCopy direction can only be reversed when the previous physical background copy has completed. If the background copy is still in progress, the new Incremental FlashCopy attempt fails. You can instruct DFSMSdss to wait for background copy to complete by specifying the FCWAIT keyword. See the FCWAIT keyword description for more information.
FCINCREMENTAL specifies that the full volume FlashCopy relationship remains in effect (persists) after the background copy has completed and subsequent changes to the source and target volumes are tracked. You can specify the INCREMENTALLAST keyword instead of FCINCREMENTAL If you want DFSMSdss to initiate FlashCopy of the final increment, stop tracking the changes, and have the relationship ended when background copy has completed.