STONITH ("Shoot The Other Node In The Head" or "Shoot The Offending Node In The Head"), sometimes called STOMITH ("Shoot The Other Member/Machine In The Head"), is a technique for fencing in computer clusters.[1] STONITH was first released for Linux-HA but has since become available for Open BSD and Solaris, etc.
Fencing is the isolation of a failed node so that it does not cause disruption to a cluster. As its name suggests, STONITH fences failed nodes by sending a message to remotely power down the failed node.
Multi-node error-prone contention in a cluster can have catastrophic results, such as if both nodes try writing to a shared storage resource. STONITH provides effective, if rather drastic, protection against these problems.