Both cluster nodes and quorum devices vote to form quorum. By default, cluster nodes acquire a quorum vote count of one when they boot and become cluster members. Nodes can also have a vote count of zero, for example, when the node is being installed, or when an administrator has placed a node into maintenance state.
Quorum devices acquire quorum vote counts based on the number of node connections to the device. When a quorum device is set up, it acquires a maximum vote count of N-1 where N is the number of connected votes to the quorum device. For example, a quorum device connected to two nodes with non zero vote counts has a quorum count of one (two minus one).
You configure quorum devices during the cluster installation, or later by using the procedures described in the Sun Cluster 3.1 System Administration Guide.
A quorum device contributes to the vote count only if at least one of the nodes to which it is currently attached is a cluster member. Also, during cluster boot, a quorum device contributes to the count only if at least one of the nodes to which it is currently attached is booting and was a member of the most recently booted cluster when it was shut down.