chrcrelationship

Use the chrcrelationship command to modify certain attributes of an existing relationship, such as to add a relationship to a consistency group to remove a relationship from a consistency group, and to change the name of the relationship. You can change one attribute at a time.

Syntax

Read syntax diagramSkip visual syntax diagram chrcrelationship -masterchangemaster_change_vdisk_idmaster_change_vdisk_name-auxchangeaux_change_vdisk_idaux_change_vdisk_name-nomasterchange-noauxchange-namenew_name_arg-consistgrpconsist_group_idconsist_group_name-noconsistgrp-cycleperiodsecondsperiod-cyclingmodenonemulti-global-metrorc_rel_idrc_rel_name

Parameters

-masterchange master_change_vdisk_id | master_change_vdisk_name
(Optional) Specifies a change volume association for the master volume in the relationship.
-auxchange aux_change_vdisk_id | aux_change_vdisk_name
(Optional) Specifies a change volume association for the auxiliary volume in the relationship.
-nomasterchange
(Optional) Specifies a defined change volume on the master volume must be removed from the relationship.
Note: To use this parameter the specified change volume must no longer be in use by the relationship, including change volumes of a running relationship (inconsistent_copying, consistent_copying, or consistent_synchronized).

It does not include a primary change volume of a stopped relationship. A secondary change volume of a relationship that is stopped from consistent_copying is considered in use if the change volume is supplying the consistent image. If this change volume needs to be removed, the relationships must first be stopped by specifying stoprcrelationship -access to apply the consistent image to the secondary volume.

-noauxchange
(Optional) Specifies a defined change volume on the auxiliary volume must be removed from the relationship.
Note: To use this parameter the specified change volume must no longer be in use by the relationship, including change volumes of a running relationship (inconsistent_copying, consistent_copying, or consistent_synchronized).

It does not include a primary change volume of a stopped relationship. A secondary change volume of a relationship that is stopped from consistent_copying is considered in use if the change volume is supplying the consistent image. If this change volume needs to be removed, the relationships must first be stopped by specifying stoprcrelationship -access in order to apply the consistent image to the secondary volume.

-name new_name_arg
(Optional) Specifies a new label to assign to the relationship.
-consistgrp consist_group_id | consist_group_name
(Optional) Specifies a new consistency group to assign the relationship to.
-noconsistgrp
(Optional) Removes the specified relationship from a consistency group, making the relationship a stand-alone relationship.
-cycleperiodseconds period
(Optional) Specifies the cycle period in seconds. The minimum cycle period value is 60 seconds (1 minute) and the maximum is 86400 seconds (1 day). The default is 300 seconds (5 minutes).
This parameter defines an optional cycle period that applies to Global Mirror relationships with a cycling mode of multi. A Global Mirror relationship that uses the multi cycling_mode performs a complete cycle at most once each period.
-cyclingmode none | multi
(Optional) Specifies the behavior of Global Mirror for this relationship.
  • Specifying none, the default, gives identical behavior to Global Mirror in previous versions of FlashSystem 5000 .
  • Specifying multi uses the cycling protocol.
To start a relationship with cycling_mode set to multi, change volumes must be defined for the relationship.
Note: The cycling_mode can be changed only when the relationship is stopped and in consistent_stopped or inconsistent_stopped status.
-metro
(Optional) Specifies the change in the relationship's copy type and converts a Global Mirror (with or without change volumes) relationship to a Metro Mirror relationship.
Remember: To use this parameter that the relationship must be stopped (inconsistent_stopped, consistent_stopped, or idling.
-global
(Optional) Specifies the change in the relationship's copy type and converts a Metro Mirror relationship to a Global Mirror relationship. This parameter is not mutually exclusive with -cyclingmode. If you do not specify -cyclingmode and the relationship is Metro Mirror, the cycling_mode value is none.
Remember: To use this parameter that the relationship must be stopped (inconsistent_stopped, consistent_stopped, or idling).
rc_rel_name | rc_rel_id
(Required) Specifies the ID or name of the relationship.

Description

This command modifies the specified attributes of the supplied relationship, one attribute at a time. In addition to changing the name of a consistency group, this command can be used for the following purposes.
Remember:
  • All parameters are mutually exclusive except for the -cyclingmode, which is mutually exclusive with all parameters but -global.
  • One of the optional parameters must be specified.
Note: You cannot set cycling mode to multi-cycling mode if the primary and secondary volumes are different sizes.
  • You can add a stand-alone relationship to a consistency group by specifying the -consistgrp parameter and the name or ID of the consistency group. The relationship and consistency group must be connected when the command is issued and must share the following components:
    • Master system
    • Auxiliary system
    • State (unless the group is empty)
    • Primary (unless the group is empty)
    • Type (unless the group is empty)
    • Cycling mode (unless the group is empty)
    When the first relationship is added to an empty group, the group takes on the same state, primary (copy direction), type (Metro Mirror or Global Mirror), and cycling mode as the relationship. Subsequent relationships must have the same state, copy direction, and type as the group in order to be added to it. A relationship can belong to only one consistency group.
  • You can remove a relationship from a consistency group by specifying the -noconsistgrp parameter and the name or ID of the relationship. Although you do not have to specify or confirm the name of the consistency group, verify which group the relationship belongs to before you issue this command.
    This form of the modify relationship command succeeds in the connected or disconnected states. If the systems are disconnected the relationship is only removed from the consistency group on the local system, at the time the command is issued. When the systems are reconnected, the relationship is automatically removed from the consistency group on the other system. Alternatively, you can issue an explicit modify (chrcrelationship) command to remove the relationship from the group on the other system while it is still disconnected.
    Note: If you remove all relationships from the group, the relationship type is reset to empty_group. When you add a relationship to the empty group, the group again takes on the same type as the relationship.
  • To move a relationship between two consistency groups, you must issue the chrcrelationship command twice. Use the -noconsistgrp parameter to remove the relationship from its current group, and then use the -consistgrp parameter with the name of the new consistency group.

You can change a relationship or consistency group between copy types even if replication is stopped. Consistency protection is preserved across all types, so a relationship or consistency group that is in consistent_copying state before it is stopped retains the consistent copy on the secondary system when the copying type is changed.

If you add a consistent_stopped relationship that uses consistency protection to a consistent_stopped consistency group that is not using consistency protection, the system attempts to trigger consistency protection on the consistency group that is not currently using consistency protection. If the relationship or consistency group that is not currently using consistency protection does not have secondary change volumes that are defined, specifying chrcrelationship -consistgrp fails. If you add a relationship to a consistency group where at least one is using consistency protection, the resulting consistency group is not mutually consistent, which means that the data on the secondary system for the relationship that is being added is inconsistent with the data on the consistency group. It also means that enabling access to the volume fails.

For intersystem relationships
  • The -name, -consistgrp, -cycleperiodseconds and -cyclingmode parameters can only be specified when the two systems are connected. If the two systems become disconnected while the command is being processed, the command might be completed with the change performed on the system that received the task invocation only (and the other system is updated upon reconnection). The -cycleperiodseconds and -cyclingmode parameters can be specified only on stand-alone relationships (not members of a consistency group).
  • The -masterchange and -nomasterchange parameters can only be specified when you run the chrcrelationship command on the master system for the relationship, and the -auxchange and -noauxchange parameters can only be specified when you run the chrcrelationship command on the auxiliary system for the relationship.
Remember: You cannot specify a master and auxiliary change volume in the same command.
A change volume must be:
  • Used by the relationship that owns it.
  • In the same I/O group as the associated master or auxiliary volume.
  • The same size as the associated master or auxiliary volume.
A change volume is owned and used by the associated Remote Copy relationship. Therefore, it cannot be:
  • Mapped to a host
  • Used as source or target of any FlashCopy® maps
  • Part of any other relationship
  • A file system disk
Assigning a change volume to a relationship requires new FlashCopy mappings to be created between the master or auxiliary volume and the associated change volume. Therefore, there must be sufficient deallocated FlashCopy memory in the target I/O group or the command fails.
Note: You cannot use this command if cloud snapshot is enabled on the volume or the volume owner type is cloud_backup.

If the cycle_period_seconds for the relationship does not match that of the consistency group it is added to, the newly added relationship copies the cycle_period_seconds value from the group. If later removed from the group, the copied cycle_period_seconds value remains.

When a Global Mirror relationship with a cycling_mode value of multi is added to a group that is not empty, both the group and the relationship must be stopped.

An invocation example to change a relationship name from rccopy1 to testrel

chrcrelationship -name testrel rccopy1
The resulting output:
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An invocation example to add relationship rccopy2 to group newgroup

chrcrelationship -consistgrp newgroup rccopy2
The resulting output:
No feedback

An invocation example to remove relationship rccopy3 from whichever consistency group it is a member of

chrcrelationship -noconsistgrp rccopy3
The resulting output:
No feedback

An invocation example

chrcrelationship -cyclingmode multi relB

The resulting output:

No feedback

An invocation example

chrcrelationship -cycleperiodseconds 60 relC

The resulting output:

No feedback