Optional parameters

NO

The required parameters address CKD devices. The default is NO.

YES

Specifies that the required parameters in this command target fixed block devices using a CKD access device.

NO

The primary volume is not eligible to be secondary in another PPRC pair. The default is NO.

YES

The primary volume is eligible to be secondary in another PPRC pair.

Note: CASCADE(YES) is not valid with the ACTION parameter.

YES

• Specifying FORCE(YES) with MODE(INCRES) indicates that normal validation that the volumes in the request have an intermediate volume in common is bypassed.
• Specifying FORCE(YES) with ACTION(FAILOVER) or ACTION(FAILBACK) indicates that validation that the specified secondary is the existing suspended device in the existing relationship for the specified primary in FAILOVER mode is bypassed.

NO

• Specifying FORCE(NO) with MODE(INCRES) indicates the following validation:
  • The current failed secondary device for the primary specified, and the current failed primary device for the secondary specified are the same device.
• Specifying FORCE(NO) with ACTION(FAILOVER) or ACTION(FAILBACK) indicates the following validation:
  • The devices specified in the establish request are currently part of a suspended relationship (in failover state for ACTION(FAILBACK)).

YES

The auto resync capability should be enabled for the Global Copy pair. This is the default.

NO

The auto resync capability should be disabled for the Global Copy pair.

You may want to use NO to disable the auto resync capability when the secondary of the Global Copy pair is or will be the source of a Space Efficient FlashCopy® relationship. An outage that results in many updates that must be copied when the pair is resynchronized could cause the space efficient repository to reach warning levels or even be filled.

START

Specifies the change recording mechanism should be started.

STOP

Specifies the change recording mechanism should be stopped

NOCOPY

Used in recovery scenarios, where the incremental resync change recording mechanism needs to be started. INCRESYNC(NOCOPY) indicates that the change recording bitmaps do not need to be initialized with all bits on. Thus, when MODE(INCRES) is used to establish the primary device to a different secondary, a full copy is not done. The reason is that in the recovery environment where this is used, the intended devices are already in sync, except for the changes made after the incremental resync change recording mechanism is started.

Note: If the INCRESYNC(NOCOPY) parameter is specified in scenarios other than where it is intended, this could cause you to make the recovery environment vulnerable to data integrity exposures.

COPY

Specifies that PPRC copy all tracks on the primary volume to the secondary volume. COPY is the default mode.

Note: MODE(COPY) is not valid with the ACTION parameter.

NOCOPY

Specifies that only those tracks on the primary volume that are updated after this command is issued are to be copied to the secondary volume. Specify this mode only if the volumes are exact copies of each other.

The NOCOPY option assumes that the specified volumes are fully synchronized at the time the copy is started. Ensure that no I/O operations occur to either volume prior to starting the copy operation. This is necessary in order to protect the data integrity of the two volumes.

The following notes apply only when the volumes of a PPRC volume pair are not of the same device capacity (volumes do not have the same number of cylinders):

For PPRC CKD Volume Pairs of Different Device Capacity:

1. If you have established or reestablished this PPRC volume pair without specifying COPY, run ICKDSF REFORMAT REFVTOC on the primary volume after you establish the pair. Doing so allows the VTOC and indexed VTOC information to accurately represent the primary volume.
2. If you switch the primary and secondary of this pair at any time, run ICKDSF REFORMAT REFVTOC on the new primary volume. Doing so allows the VTOC and indexed VTOC information to accurately represent the new primary volume.
3. If you remove the secondary volume from the volume pair for use as a simplex volume, you should run ICKDSF REFORMAT REFVTOC on the volume. Doing so allows the VTOC and Indexed VTOC information to accurately represent the secondary volume.

INCRES

Causes an incremental resynchronization using the change recording bitmaps to limit the tracks to be copied. MODE(INCRES) is mutually exclusive with the ACTION keyword and with the INCRESYNC keyword.

RESYNC

Specifies that PPRC reestablish a suspended copy. Before you issue this option, be certain that either the primary and secondary volumes are both in a suspended state, or the secondary is in a simplex state and the primary is suspended. PPRC only copies from the primary volume to the secondary volume the cylinders that were updated during the period of suspension.

SYNC

Specifies that data is transmitted synchronously to PPRC secondary volumes. SYNC is the default value. You can specify this option for all storage controls that support PPRC operations. Specifying OPTION(SYNC) will cause a PPRC extended distance pair in PENDING XD or SUSP(n).XD state to change to a synchronous operation.

XD

Specifies that data is transmitted from primary volumes to secondary volumes in PPRC extended distance mode. The IBM® ESS must have the PPRC extended distance feature installed and active for this option to be accepted. The CRIT(YES) and MODE(NOCOPY) parameters are mutually exclusive with the OPTION(XD) parameter.

For information about PPRC extended distance, see Managing PPRC extended distance mode.

Note: OPTION(XD) is not valid with CRIT(YES). OPTION(XD) is not valid with MODE(NOCOPY) if you also specify ACTION(FAILOVER) or ACTION(FAILBACK).

NO

Specifies that, if the secondary volume that is attached to an ESS subsystem appears to be online to any host system, the CESTPAIR command will fail with an error. The default is NO.

YES

Specifies that the CESTPAIR command be processed even if the ESS secondary volume appears to be online to a host system.

Table 1 shows the result of different PACE parameter values.

NO

Specifies that, following an I/O completion error, PPRC allows subsequent write requests to the PPRC primary volume. The primary storage control will perform change recording. The default is NO.

YES

This should only be specified at the request of an IBM representative. Specifies that if an I/O error occurs, PPRC either allows or does not allow subsequent writes, depending on how the storage subsystem is configured. The PPRC pair then remains in a suspended state until you correct the problem and issue either a CESTPAIR RESYNC or CDELPAIR command. See Considering the PPRC solution and Examining disaster recovery from a system viewpoint for related information.

Note: CRIT(YES) is not valid with OPTION(XD), CASCADE(YES), the ACTION parameter, or with OPENDVCS(YES).

FAILOVER

Specifies that the direction of the PPRC pair is to be reversed and change recording is to begin. Upon completion of the command, the device that was previously the secondary becomes the suspended primary device in the PPRC pair. Change recording begins on the suspended primary, to be used in a subsequent failover operation. ACTION(FAILOVER) is not valid with MSGREQ(YES).

FAILBACK

Specifies that the connection between the primary and secondary devices has been repaired and the original primary/secondary relationship is to be restored. Changed tracks recorded since failover was issued are copied to the specified secondary device.

If the secondary is in a soft fence state, the soft fence state is cleared.

MTFAILOVER

Specifies that a multi-target configuration should be created from a cascaded configuration. For example, in a cascaded configuration, H1->H2->H3, where H1 is the primary, issuing a CESTPAIR command with ACTION(MTFAILOVER) to the middle device, H2, causes a multi-target configuration (H2->H1 and H2-H3) in place of the previous cascaded failover state.

For more information, refer to Converting to Multi-Target Mirror.

NO

Specifies that the command is complete as soon as you initiate the request to the storage control. PPRC does not wait for the copy operation to complete before issuing completion messages. The default is NO.

YES

Specifies that PPRC wait until the initial full-volume copy operation is complete before issuing completion message ANTP0001I. This option is not valid when OPENDVCS(YES) or ACTION(FAILOVER) is specified.

NO

Any reserve that exists on the specified secondary device should not be reset. This is the default.

YES

If there is a reserve on the specified secondary device, that reserve should be reset.

NO

Indicates that secondary cannot be a space efficient volume. The default value is NO.

YES

Indicates that the secondary volume can be a space efficient volume. If YES is specified and the secondary volume is not a space efficient volume, the command is processed as if the keyword was not specified.

If you omit the parameter, the command is issued to the device that is logically in subchannel set 0. If a swap has occurred, this could be the device that was defined in an alternate subchannel set in the I/O configuration (IODF), with HCD.