PowerHA SystemMirror for AIX Enterprise Edition
Increasingly, IT organizations are being asked to provide multi-site configurations for disaster recovery as well as to periodically demonstrate compliance to corporate policy and regulations. In the past, this was typically a recover from tape operation or a reboot operation at the remote location. The PowerHA SystemMirror Enterprise Edition is essential for clients who must both protect themselves from site-wide failures as well as to be able to readily demonstrate the capability to do so. Storage servers or host based replication provide the data replication services and the Enterprise Edition enables the management and automation of the failover process. With V7 of PowerHA SystemMirror Enterprise Edition we introduce HyperSwap with the IBM DS8800 in the Metro Mirror configuration. This advanced technology provides the capability for a cluster to span two sites with the storage and servers cross coupled in a manner that keeps the application resilient through either a storage server or a production server outage (for active-active workloads). Geographically dispersed configurations can be deployed via a stretched cluster configuration defined as having a single cluster repository or via a linked cluster configuration with two independent yet linked cluster repositories. A stretch cluster can also be deployed with the Standard Edition and LVM mirroring in a cross site mirror configuration similar to what clients have deployed in previous versions. The stretched cluster configuration provides three levels of cluster communication redundancy via multi-cast across the network, SAN fabric and repository disk.