Determining fast replication eligibility

Fast replication is a point-in-time function that allows data to be copied from a source location to a target location. FlashCopy® on ESS devices and SnapShot on RAMAC Virtual Array (RVA) storage subsystems are examples of fast replication methods.

You can invoke the QFRVOLS query through the ANTRQST API to determine whether the source and target devices are capable and eligible for fast replication operations: FlashCopy V1 or FlashCopy V2 on the ESS or SnapShot on the RVA. If the QFRVOLS query indicates that you can use a volume as a fast replication target volume, then the volume can also be used as a fast replication source volume. Any condition that prevents a volume from being a fast replication target volume also prevents the volume from being a fast replication source volume.

The QFRVOLS query returns information about the type of fast replication capability for each volume or extent in a user-supplied volume list. If a fast replication operation cannot be performed, the QFRVOLS query information indicates why the volumes or extents are not eligible for fast replication operations.

The ANTRQST QFRVOLS query requires the following input to determine whether source and target volumes or extents are capable of fast replication operations, such as FlashCopy or SnapShot.

A control volume.
A list of target volumes (with the VOLLIST parameter) that identifies which volumes to compare to the control volume.
A request that the volumes listed in the VOLLIST be checked for source or target volume capability for FlashCopy operations.
An indication as to whether PPRC primaries are included as eligible target volumes.
An indication as to whether space efficient volumes are included as eligible target volumes.

The output returns information about each volume or extent in the user-supplied volume list, which indicates whether a volume or extent can be used for fast replication.

For additional information about the parameters required for the QFRVOLS request, refer to Subparameters for REQUEST=QFRVOLS.