Replication

Policy-based replication provides simplified configuration and management of asynchronous replication between two systems.

Policy-based replication uses volume groups to automatically deploy and manage replication. This feature significantly simplifies configuring, managing, and monitoring replication between two systems. Policy-based replication simplifies asynchronous replication with the following key advantages:
  • Replication is configured on the volume group and all volumes are replicated based on the assigned policy.
  • Uses volume groups instead of consistency groups. With volume groups, all volumes are replicated based on the assigned policy.
  • Simplifies administration by managing replication on the volume group, reducing the number of objects that need to be managed and monitored.
  • Automatically manages provisioning on the remote system.
  • Supports easier visualization of replication during a site failover.
  • Automatically notifies you when the recovery point objective (RPO) is exceeded.
  • Easy-to-understand status and alerts on the overall health of replication.
Policy-based replication is supported on the following products:
  • IBM® SAN Volume Controller
  • IBM Storage FlashSystem 9500
  • IBM Storage FlashSystem 9200
  • IBM Storage FlashSystem 9100
  • IBM Storage FlashSystem 7300
  • IBM Storage FlashSystem 7200
  • IBM Storage FlashSystem 5200 (requires a minimum of 128 GiB memory in each node canister)
  • IBM Storage FlashSystem 5300 (requires a minimum of 128 GiB memory in each node canister)
  • IBM Storage FlashSystem 5045 (requires a minimum of 32 GiB memory in each node canister)
  • IBM Storage Virtualize for Public Cloud

To learn more about concepts and objects that are related to the policy-based replication, see the Overview topics and Volume groups.

Prerequisites

For more information, see Planning for asynchronous disaster recovery replication.

Configuring policy-based replication

As part of policy-based replication, the management GUI provides an interactive checklist to guide you through all the configuration steps. For example, the checklist provides links to launch directly to the remote system to complete the partnership and pool linking configuration steps, and indicates when each step is completed. You can use this interactive checklist when you are configuring policy-based replication for the first time.

The following tasks are necessary to configure policy-based replication:
Creating partnership for replication
For policy-based replication, a two-site partnership must be configured between the production and recovery systems. The partnership establishes a secure connection between systems that use either Fibre Channel or IP protocols. To configure partnership, see Creating partnership for replication.
Creating provisioning policies (optional)
A provisioning policy is an entity that defines a set of rules for allocating capacity from a pool. Any volumes that are created in the pool adopt the capacity-saving methods that are defined in the provisioning policy. . A provisioning policy simplifies the volume provisioning process by specifying capacity savings methods per pool.. For more information, see Creating provisioning policy and assigning to pools.
Creating a linked pool
For more information, see Creating linked pools.
Creating replication policies
You can use the management GUI interface and command-line interface (CLI) for creating replication policies. To configure replication policy, see Creating replication policies.
Creating volume group and assigning replication policy
Policy-based replication uses volume groups and replication policies to deploy and manage replications. After you create a replication policy, you need to create a volume group and assign it to the replication policy. When you add source volumes to the volume group on a production system, they are replicated together to the recovery system to ensure consistent replication. In addition, recovery copies of volume groups are immutable. Policy-based replication significantly simplifies configuring, managing, and monitoring replication between two systems. For more information, see Creating a volume group and assigning replication policy.

If you currently use Global Mirror or Global Mirror with change volumes configurations to replicate data between two systems, it is possible to convert to policy-based replication from these configurations. Other remote copy functions, like 3-site partnerships, nondisruptive volume migration, and Metro Mirror cannot be converted to policy-based replication without first converting any relationships to Global Mirror.

Managing policy-based replication

After you configure or convert to policy-based replication on the partnered systems, you can monitor and manage policy-based replication and associated objects with either the management GUI and the command-line interface. For more information, see the following topics:

Monitoring and troubleshooting policy-based replication

Policy-based replication supports simplified monitoring of replication status and RPO and interactive error resolution through directed maintenance procedures (DMP). For more information, see the following topics:

For more information on partnerships, see Partnerships.