Symptoms
Hardware failure in Single Control Station array.A VNX Control Station failure occurred and before the hardware was replaced a fault occurred which should have normally triggered a data mover failover, but no data mover failover happened.
Cause
Array with a Single Control Station, when a hardware failure occurred on the control station resulting it being unbootable or unable to run correctly the NAS Control Station services for the management of the array, any subsequent event which would normally trigger a failover of the data mover will not. The NAS Control Station and its management services are required to perform a data mover failover. An inoperable control station or one that has the NAS Services in a stopped state cannot trigger a data mover failover.In a dual control station configuration a failure of the primary control station services or hardware will result in the standby peer control station forcibly taking over the role as the primary control station , this is triggered when the peer control station fails to receive responses to it's management heartbeats or the heartbeat responses exceed a timeout value.
Resolution
For a control station that is online, run nas_checkup command to confirm if there are any reported hardware faults or software faults reported. If there are hardware faults, VNX Support should be engaged to resolve. A warning for a software issue may be possible to resolve using the Dell EMC Knowledgebase https://support.emc.com/Always run a collect support materials on the control station if possible to capture logs and the current state before making any changes so these can be analyzed if required.To check specifically for a hardware fault only the commands below can be used, for enclosure status, the data mover enclosure number is specified after (-e)$ nas_inventory -tree$ /nas/sbin/enclosure_status -e 0 -v
