The second solution to the quorum problem in a two-node cluster configuration is to implement an additional quorum disk. A quorum disk is a shared storage block device both cluster nodes have access to. The Cluster and cluster nodes use this disk as cluster configuration storage and also as a secondary heartbeat communication channel. A quorum disk brings another vote to the cluster configuration, therefore eliminating the problem of a two-node cluster configuration quorum. A quorum disk can also be used as a secondary cluster heartbeat communication channel, and can therefore resolve cluster split-brain situations in the case of network communication failure.
With the quorum disk implemented, in the event of a cluster node failure quorum is reached by one cluster node vote and one quorum disk vote, and the cluster can continue to perform its normal operation.