fence_ack_manual failed with error "can't open /tmp/fence_manual.fifo" when fence_manual is configured on Red Hat Cluster Suite

Solution Unverified - Updated -


  • After running fence_ack_manual -s <IP>, an error is received:
# fence_ack_manual -s 

Warning:  If the node "" has not been manually fenced 
(i.e. power cycled or disconnected from shared storage devices) 
the GFS file system may become corrupted and all its data 
unrecoverable!  Please verify that the node shown above has 
been reset or disconnected from storage. 

Are you certain you want to continue? [yN] y 
can't open /tmp/fence_manual.fifo: No such file or directory


  • Red Hat Enterprise Linux (RHEL); including:
    • Red Hat Cluster Suite 4+
    • Red Hat Enterprise Linux Server 5 (with the High Availability Add on)
  • Red Hat Cluster Suite (RHCS) cluster with 2 or more nodes
  • The fence device used is fence_manual (unsupported in productions environments):
# grep fence_manual /etc/cluster/cluster.conf
        <fencedevice agent="fence_manual" name="manual_fence"/>
  • Cluster nodes have lost contact of each other, and have triggered fence_manual. Manual intervention is required to recover.

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