Pool links
High availability and disaster recovery replication require the storage pools that are used for creating replicated volumes to be linked between systems. When a volume is created on the active management system for HA, or on the production system for DR, pool links define the pool that is used on the remote system to create the replicated volume.
For SAN Volume Controller systems that use a stretched system topology with mirrored volumes, only the pools that are in site 1 need to be linked.
Use of the management GUI to configure pool links simplifies the process by allowing pools to be linked from a single system without needing to login to the other system. Configuration can also be performed by using the CLI or the REST API, connecting to each system with pools to be linked.
Additionally, if child pools currently exist on one system only, you can use the management GUI on the partnered system to create and link a child pool in a single step. The management GUI simplifies the process of creating a linked pool on the second system, displaying the properties like name, capacity, and provisioning policy from the first system.
When you configure pool links by using the GUI, you can optionally assign a provisioning policy to the pools that you are linking. Provisioning policies control how capacity is provisioned on new volumes that are created in the linked pool. Pools on each partnered system can be assigned provisioning policies with different capacity savings methods. The system creates two default provisioning policies when the first parent pool is created. You can create more user-defined policies to specify alternative capacity savings if desired. The system creates fully provisioned volumes if a provisioning policy is not configured. For more information, see Provisioning policy.
Using the management GUI
When adding high availability or disaster recovery, the management GUI guides you through the required steps to link storage pools between systems, and optionally assign provisioning policies on each linked pool.
To link extra pools later, or remove the links between pools, go to the page in the management GUI and select the pool that you want to modify. Right-click on the pool and select the action-prompt to Add Pool Link for Replication or Modify Pool Links for Replication as required.
Using the command-line interface
Pools on partnered systems are linked if they have the same replication_pool_link_uid value. To identify pools that are linked, use the lsmdiskgrp command on each system.
To modify or remove the links between pools by using the command-line interface, use the chmdiskgrp command.