Eliminating single points of failure in a PowerHA SystemMirror cluster

The PowerHA® SystemMirror® software enables you to build clusters that are both highly available and scalable by eliminating single points of failure (SPOF). A single point of failure exists when a critical cluster function is provided by a single component.

If that component fails, the cluster has no other way to provide that function and essential services become unavailable. For example, if all the data for a critical application resides on a single disk that is not mirrored, and that disk fails, the disk is a single point of failure for the entire system. Client nodes cannot access that application until the data on the disk is restored.