Fence Agents for Red Hat Cluster - APC over telnet/ssh agent

 Red Hat Fence Agents is a collection of scripts to handle remote power
 management for several devices. They allow failed or unreachable nodes to be
 forcibly restarted and removed from the cluster.
 .
 fence_apc is an I/O Fencing agent which can be used with the APC network power
 switch. It logs into device via telnet/ssh and reboots a specified outlet.
 Lengthy telnet/ssh connections should be avoided while a GFS cluster is running
 because the connection will block any necessary fencing actions.