IBM® PowerHA® SystemMirror® for AIX® (formerly IBM HACMP™) was first available in 1991 and is now in its 24th release, with over 20,000 PowerHA clusters in production, worldwide. IBM PowerHA SystemMirror is recognized as a robust, mature high availability solution. PowerHA supports a wide variety of configurations, and offers a great deal of flexibility to the cluster administrator. With this flexibility comes the responsibility to make wise choices because many cluster configurations are available that work regarding the cluster passing verification and being brought online, but those configurations are not ideal in terms of providing availability.
This IBM Redpaper™publication describes choices that the cluster designer can make, and suggests the alternatives that can achieve the highest level of availability.
Designing high availability
PowerHA in a virtualized world