PowerHA data replication technologies
PowerHA® offers several different technologies for data replication. These technologies can be used separately or sometimes combined to provide a higher level of protection against outages.
Geographic mirroring is an IBM® replication technology and can be used with any storage. Data is replicated between two copies of the independent ASP, and both synchronous and asynchronous replication is supported. Geographic mirroring can protect against both server and storage outages.
For customers with external storage, there are several technologies available. Switched logical units allow the switching of one copy of the data from one system to another and protect against server outages. Metro Mirror and Global Mirror are the synchronous and asynchronous replication technologies for external storage and protect against both server and storage outages by replicating the data from the primary copy of the IASP to a backup copy. HyperSwap® is a DS8000® technology, which provides a near zero outage in the case of storage outages. FlashCopy® is a point in time copy mechanism, which can be used in combination with any of the technologies for backups and for other uses.