Solution overview
The High Availability (HA) solution uses Storage Partitions, a configuration object that is the single point of management for HA objects. These partitions contain volumes, volume groups, hosts, and host-to-volume mappings.
Within a partition:
- All volumes are in volume groups.
- Mappings can be created only between volumes and hosts in the same partition.
An HA replication policy can be associated with a partition. The HA replication policy defines the two systems that are connected by a partnership that are providing the HA solution.
When the partitions are associated with an HA replication policy, all the objects that are contained in the partition are automatically configured across both systems that are associated with the replication policy. Hosts that are created in a partition will be able to discover paths to the mapped volumes through both systems. Hosts that are created with a location prioritize use of a colocated system.
Before creation of storage partitions, the systems are configured with Partnerships, Pools that are linked between systems (see Creating linked pools), Replication policies, and IP quorum application. You can configure multiple partitions for HA.
Each partition that is associated with an HA replication policy has two properties - the preferred management system and the active management system.
The active management system is the system from which all configuration tasks must be performed. If an outage or other failure happens on the current active management system, the active management system will automatically fail over to the other system.
The preferred management system is the system that you would like to be the active management system under ideal conditions. If the active management system and the preferred management system are not the same system, the system will automatically failover the active management system back to the preferred management system when it is able. The preferred management system can be changed by the user.
Everything in a configured Storage Partition is highly available. When required, both management and I/O fail over between systems to maintain access.
You can configure more volumes, volume groups, hosts, and host-to-volume mappings at any time, either by adding to an existing partition or by creating a new one.
The IP Quorum application determines which system becomes the active management system and avoids a scenario where both halves of the High Availability solution continue to process the same partition.