High availability technologies

Whether you need high availability for your business applications or are looking to reduce the amount of time it takes to perform daily backups, IBM® i high availability technologies provide the infrastructure and tools to help achieve your goals.

All IBM PowerHA® SystemMirror® for i technologies, as well as some Business Partner high availability products, are built on IBM i cluster resource services, or more simply clusters. Cluster provides the underlying infrastructure that allows resilient resources, such as data, devices and applications, to be automatically or manually switched between systems. It provides failure detection and response, so that in the event of an outage, cluster resource services responds accordingly, keeping your data safe and your business operational.

The other key technology that is used by PowerHA technologies is independent disk pools. Independent disk pools allow data and applications be stored on disks that might or might not be present when the system is operational. When independent disk pools are a part of a cluster, the data and applications that are stored within them can be switched to other systems or logical partitions. There are several different technologies that are based on independent disk pools, including switched disks, geographic mirroring, Metro Mirror, Global Mirror, and DS8000® HyperSwap® with independent auxiliary storage pools (IASPs). Determining which technology to base your high availability solution upon depends on several factors. The topic, High availability overview, provides a high-level comparison of these technologies along with criteria that you can use to determine which technologies are most suited for your needs.

In IBM Knowledge Center, the terms IASP and independent disk pool are synonymous.

This topic provides descriptions of key high availability technologies, their associated concepts, and describes the different high availability management interfaces that are supported by IBM i systems.