IBM® PowerHA® SystemMirror® for AIX® 7 represents a new generation of clustering solutions for high availability and disaster recover. Based on Cluster Aware AIX (CAA), the PowerHA SystemMirror Standard Edition and the PowerHA SystemMirror Enterprise Edition offerings represent a major shift in the traditional architectural concepts of building and managing clusters for high availability and disaster recovery. Cluster Aware AIX shifts key aspects of clustering technology into the IBM AIX kernel, helping to enable simpler, more robust cluster formation and management. Cluster Aware AIX features near real-time inter-node messaging and synchronization, clusterwide health management, and multichannel redundancy. With Technology level (TL) 3, Standard Edition can be configured with unicast (the default option) or multicast communications.
The PowerHA SystemMirror V7.1 offering introduces new capabilities that include stretched clusters and linked clusters, both of which enable kernel level communications between geographically dispersed nodes for more robust configurations. The linked cluster topology has an independent cluster repository at the primary and secondary sites, which enables clients to have two data centers that are linked by unicasting. A stretched cluster configuration has a single repository and supports multicasting and multichannel communications and unicast communications with TL 3.