Managing z/OS HyperSwap or hardened freeze across multiple sessions within the same sysplex

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You can manage z/OS HyperSwap or hardened freeze operations across multiple sessions within the same sysplex.

About this task

Copy Services Manager supports the ability to enable z/OS HyperSwap on DS8000 sessions that contain Metro Mirror pairs. However, only one HyperSwap configuration can be loaded at a time within a sysplex. This limitation means that only a single session that is associated with a particular sysplex can load a HyperSwap configuration.

However, in specific cases you might want all of your Metro Mirror pairs to be enabled with HyperSwap. But only a subset of those pairs requires an extra replication to a third site. For example, you might have production and development servers that are running Metro Mirror between two local sites and want both of these servers to be HyperSwap capable. But to save on replication and storage costs, perhaps only the production data needs to be replicated to the third site in a disaster.

Starting with the Copy Services Manager 6.2.0 release, you can now configure your environment so that multiple sessions of different session types can be HyperSwap capable within the same sysplex. With this feature, you can have asymmetric configurations for the data that you are replicating, while also ensuing that all of the data is HyperSwap capable.

Follow these steps to set up multiple sessions on the same sysplex to be HyperSwap capable:

Procedure

  1. Log in to the Copy Services Manager GUI as a user with administrative privileges.
  2. Click Sessions.
  3. From the Sessions Overview panel, click Session Actions > View/Modify > Properties.
  4. In the session properties for each session, clear the Manage Hx-Hy with HyperSwap and the Enable Hardened Freeze options, if checked. This action temporarily disables HyperSwap or hardened freeze.
  5. In the session properties for each session, associate the session to the same Sysplex.
  6. On the Session Details panel, or by selecting View/Modify > Set Consistency Group name, modify the consistency group name for the role pair (for example, H1-H2) in each session that will be HyperSwap capable, to the same name. The consistency group name that is defined on the Metro Mirror role pair is used to load the HyperSwap configuration on to z/OS.
  7. In the session properties for each session, select the Manage Hx-Hy with HyperSwap option again.

Results

When all pairs in all sessions that have the same consistency group name for the HyperSwap role pair, reach a Prepared state, a load is issued that contains the configuration of all Metro Mirror pairs across all the sessions.

If there are multiple sessions with the same consistency group name defined, a configuration does not load until all the pairs across all the sessions are ready and in a Prepared state. If any session has pairs in a state other than Prepared, except for the Defined state, no load is issued and a warning is placed on the session until all sessions reach the Prepared state and load a configuration.

Special considerations: You can also use this feature to manage hardened freeze across multiple sessions. If you use the same process that was described in the previous task, except select only the hardened freeze option in step 7, multiple sessions load a hardened freeze configuration on z/OS. You can use this method to manage data in separate sessions and session types, but keep consistency across those sessions in a disaster. For example, you might have a Metro Global Mirror and a Metro Mirror session in your configuration. Without the consistency group name, you can set up hardened freeze for both sessions individually. However, if the Metro Global Mirror session processed an unexpected suspend and Suspended the session, the Metro Mirror session does not suspend. With the same consistency group name defined on the session, a single hardened freeze configuration is loaded on z/OS so that when an unexpected suspend occurs, both sessions are suspended consistently.

All sessions that have the same consistency group name defined need to have the same load type defined. If multiple sessions have the same consistency group name defined, but one is set up with HyperSwap and another with hardened freeze, the load does not occur and an error message appears on the session. To run separate load types, the consistency group name needs to be removed first. After you remove the consistency group name, then the session can load a different type of configuration.