Global Mirror Failover/Failback with Practice session properties

The properties are displayed on different tabs in the notebook. Use the Session Options tab to set properties that apply to the entire session. Use the individual role pair option tabs to set properties that apply to specific role pairs. For example, options for the H1-J2 role pair are contained in the H1-J2 Options tab.

Session Options

Enter the properties for the session.

Description

Type the description for this session.

Fail MM/GC if target is online (CKD only)

Select this option to fail any session commands for a Metro Mirror or Global Copy relationship if the target volume is in the Online state. For more information about this state, see the documentation for the storage system.

This option applies only to count key data (CKD) volumes.

Reset Secondary Reserves

Select this option to remove any persistent reserves that might be set on the target volumes of the copy sets when a Start command is issued for the session.

Attention: This option causes the session to overwrite all data that is on the target volume.

H1-J2 Options

Enter the properties for the role pair.

Consistency group interval time (seconds)

Type how often, in seconds, the Global Mirror session attempts to form a consistency group. A lower value possibly reduces the data exposure of the session. However, a lower value also causes the session to attempt to create consistency groups more frequently, which can increase network traffic.

Max Coordination Interval (milliseconds)

Type in the maximum amount of time, in milliseconds, for the extended-distance consistency-coordination interval. The default value for new sessions is 50 milliseconds. Setting this field to 0 is equivalent to <auto> and indicates to the storage system to use the default value.

Max CG Drain Time (seconds)

Type in the maximum amount of time, in seconds, that the consistent set of data is allowed to drain at the remote site before it fails consistency group formation. The default value for new sessions is 90 seconds. Setting this field to 0 is equivalent to <auto> and indicates to the storage system to use the default value.

Recovery Point Objective Alerts

Specify the length of time that you want to set for the recovery point objective (RPO) thresholds. The values determine whether a Warning or Severe alert is generated when the RPO threshold is exceeded for a role pair. The RPO represents the length of time in seconds of data exposure that is acceptable if a disaster occurs.

Use the following options to set the RPO threshold values. For both options, you can specify an RPO threshold in the range of 0 - 65535 seconds. The default is 0 seconds, which specifies that no alerts are generated.

Warning level threshold (seconds)

Type the number of seconds that you want to set for the warning level RPO threshold. If the RPO is greater than this value, an alert is generated.

If the value in this field is other than 0, it must be greater than the value in the Consistency group interval time (seconds) field and less than the value in the Severe level threshold (seconds) field.

Severe level threshold (seconds)

Type the number of seconds that you want to set for the severe level RPO threshold. If the RPO is greater than this value, an alert is generated and the session status changes to Severe.

If the value in this field is other than 0, it must be greater than the value in the Warning level threshold (seconds) field.

H2-I2 Options

Enter the properties for the role pair.

Persistent

Select this option to keep FlashCopy® pairs persistent on the hardware.

No Copy

Select this option if you do not want the hardware to write the background copy until the source track is written to. Data is not copied to the H2 volume until the blocks or tracks of the I2 volume are modified.

Incremental

Select this option to apply incremental changes to the target volume. After the initial FlashCopy operation, only data that changed on the source volume since the last FlashCopy operation completed is copied to the target volume. This option is only valid if the source storage system supports multiple incremental FlashCopy.

If you select this option, a persistent FlashCopy relationship is created regardless of whether you select the Persistent check box.

Reset target reserves (FB only)

Select this option to reset the SCSI reserves on the FlashCopy target volumes.

This option applies only to fixed block (FB) volumes.

Note: The SCSI reserves are reset only when the Flash command is issued, after the Reset target reserves (FB only) option is selected.

Journal Options

Reflash After Recover

Select this option to reflash a consistent set of data to the journal volume after a Recover command is issued to the session. Reflashing to the journal volume ensures that there is a consistent copy of the data to recover from if failures occur during resynchronization. If you do not select this option, the journal volumes will not have a consistent copy of the data after the recover operation. However, the space will be available when space-efficient volumes are used.