Node fencing

From Wikipedia, the free encyclopedia

Node fencing is a concept in computer clusters. A node fence (or I/O fence) is a virtual "fence" that separates nodes which may have access to a shared resource from nodes which must not. It may separate an active node from its backup. If the backup crosses the fence and, for example, tries to control the same disk array as the primary, bad things may happen. Mechanisms such as STONITH are designed to prevent this condition.