IBM High Availability Cluster Multiprocessing (HACMP TM) product was first shipped in 1991 and is now in its 15th release, with over 60,000 HACMP clusters in production world wide. It is generally recognized as a robust, mature high availability product. HACMP supports a wide variety of configurations, and provides the cluster administrator with a great deal of flexibility. With this flexibility comes the responsibility to make wise choices: there are many cluster configurations that are workable in the sense that the cluster will pass verification and come on line, but which are not optimum in terms of providing availability. This document discusses the choices that the cluster designer can make, and suggests the alternatives that make for the highest level of availability*.
* This document applies to HACMP running under AIX®, although general best practice concepts are also applicable to HACMP running under Linux®.