Metro Mirror - Global Mirror with Site 4 Replication session properties

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Use the View/Modify Properties notebook to edit properties for IBM® DS8000® Metro Mirror - Global Mirror with Site 4 Replication sessions.

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, properties for the H1-H2 role pair are contained in the H1-H2 Options tab.

Session Options

Enter the properties for the session.

Description

Type the description for this session.

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.

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, refer to the documentation for the storage system.

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

z/OS Management

Select the following options to manage IBM z/OS features for the role pair.

Enable Hardened Freeze

Select this option to enable the z/OS Input/Output Supervisor (IOS) to manage freeze operations.

Requirement: This option requires the z/OS address spaces Basic HyperSwap® Management and Basic HyperSwap API. For instructions about how to start these address spaces, see the information about preparing to use Basic HyperSwap from z/OS in the IBM Copy Services Manager Installation and Configuration Guide.

If you select this option, IOS can freeze volumes regardless of whether the copy services management server is started or stopped.

In addition, with this option you can include z/OS system volumes such as paging, database, and IBM WebSphere Application Server hierarchical file system (HFS) as Metro Mirror volumes in the session. When you select this option, IOS manages the freeze operations for all Metro Mirror volumes in the session, which prevents the copy services management server from freezing the volumes and possibly freezing itself. This option does not enable IOS to manage freeze operations for Global Mirror volumes.

If you select the Manage H1-H2 or H3-H4 with HyperSwap option for the session, this option is ignored. HyperSwap includes IOS for managing freeze operations. The Enable Hardened Freeze option ensures data integrity if copy services management server freezes and HyperSwap is not enabled for a session.

Metro Mirror Suspend Policy

Select one of the following options to specify the policy for holding or releasing input/output (I/O) after a Metro Mirror relationship is suspended. When a relationship is in a Suspended state, write operations from the source volume are no longer mirrored to the target volume.

Hold I/O after Suspend: Click this option to prevent the source volume from receiving new data after the relationship is suspended. Use this option if you want to determine the scope of the suspension before new data is written to the source volume. This option helps to ensure that the data on the source and target volumes remains the same.; To enable write operations to the source volume to continue, issue the Copy Services Manager Release I/O command for the session. If you do not issue this command, write operations are enabled when the hardware timeout value on the storage system expires.

Release I/O after Suspend: Click this option to enable the source volume to automatically receive data after the relationship is suspended. Use this option if you want to limit the effect on the applications that are writing to the source volume. This option is enabled by default.
Attention: This option can cause the data on the source volume to be different from the data on target volume.

H1-H2 or H3-H4 Options

Enter the properties for the role pair.

z/OS Management

Select the following options to manage IBM z/OS features for the role pair.

The z/OS Management options are displayed only if the copy services management server is installed on or connected to a z/OS host system. You can add a z/OS host connection to the copy services management server regardless of the operating system on which the application is installed.

When you are connected to a z/OS host system, you can manage z/OS features for volumes that are attached to the host system. In addition, you can manage these features for volumes that are attached to other z/OS systems that are connected to the host system through a sysplex.

System or sysplex: Select the z/OS system or sysplex that you want to associate with the session. Commands for z/OS features are issued to this system or sysplex. Volumes in the session must be attached to the system or sysplex to enable the features.

Manage H1-H2 or H3-H4 with Hyperswap: Select this option to trigger a HyperSwap operation, which redirects application I/O to the target volumes when a failure occurs on the host accessible volumes. HyperSwap is used to manage the H1-H2 sequence of a Metro Mirror or Metro Global Mirror session.

HyperSwap options

Disable HyperSwap: Select this option to prevent a HyperSwap operation from occurring.

Reset In Use By System on Secondary Volumes: Select this option to have the load of the configuration automatically reset the In Use By System state on all secondary volumes (UCBNALOC = OFF). When this option is not selected, a load of the configuration fails when secondary volumes are in the In Use By System state (UCBNALOC is ON). This feature is only available after APAR OA53082 is applied to the z/OS system.
Unbox Secondary Volumes: Select this option to have the load of the configuration automatically unbox all secondary volumes in the configuration. When this option is not selected, a load of the configuration fails when secondary volumes are in a boxed state. This feature is only available after APAR OA53082 is applied to the z/OS system.

On Planned HyperSwap error:: Partition out the failing system(s) and continue swap processing on the remaining system(s)
Select this option to partition out the failing system and continue the swap processing on any remaining systems.; Disable HyperSwap after attempting backout
Select this option to enable IOS to back out the HyperSwap operation, if possible, if an error occurs during HyperSwap processing. HyperSwap is disabled.

On Unplanned HyperSwap error:: Partition out the failing system(s) and continue swap processing on the remaining system(s)
Select this option to partition out the failing systems and continue HyperSwap processing on the remaining systems when a new system is added to the sysplex and the HyperSwap operation does not complete.
Requirement: If you select this option, you must restart the system.; Disable HyperSwap after attempting backout
Select this option to enable IOS to back out the HyperSwap operation, if possible, if an error occurs during HyperSwap processing. HyperSwap is disabled.

H1-J3, H2-J3, H3-J1 and H4JI 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.

Journal Options

Enter the properties for the role pair.

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.