When the master metadata server suffers a hard fault, a setmaster command is typicaly used on a subordinate server to set a new master for the cluster. However, if the newly designated master determines that the original master is still operational, the newly designated master will stop.
Ensure that the original master is really powered down and that the subordinate is up. Then,un the setmaster command on the subordinate again.
Parent topic: Metadata server logging facility messages