A node is out of 'CLAM quorum'.
AutoSupport: NODE(S) OUT OF CLUSTER QUORUM
Connectivity, Liveness, Availability Monitor (CLAM), are functions of clustered Data ONTAP 8 and is used by each node in the cluster to monitor the availability of the other nodes. When CLAM detects a communication fault on the cluster network or a node outage it will initiate an HA takeover of the isolated node(s) to maintain the service of the faulted node(s) data.
As of Data ONTAP 8.1, CLAM will only initiate an HA takeover if FCP or iSCSI is licensed and the node has LUNs or SAN LIFs. Each node in the cluster will generate and send an AutoSupport with the reason
NODE(S) OUT OF CLUSTER QUORUM containing the diagnostic data needed to identify the cause of the fault.