Q

Quorum
Voting mechanism used to guarantee that specific data necessary for recovery can be maintained consistently between all cluster members. This mechanism involves a special resource called the quorum resource. The recovery data is stored by the quorum resource, typically a physical disk or fault tolerant disk set that can be owned by one cluster node at any point in time. When the node that owns the quorum resource fails, the surviving nodes arbitrate to take over its ownership.

Each quorum resource receives one vote and that vote is transitively passed to the node that currently owns the resource. By default there is only one quorum resource per cluster. The quorum mechanism is maintained by Cluster Service's Membership Manager.

Quorum-capable resource
A cluster resource that can act as a cluster's quorum resource. A quorum-capable resource must provide a means for persistent storage of configuration information necessary for recovery and a means for arbitration. Arbitration is the process by which cluster nodes effectively negotiate for ownership of the quorum resource. The SCSI reserve and release functions are examples of this type of arbitration support. In Cluster Server version 1.0, only physical disk resources and fault tolerant disk set resources are quorum-capable.
Quorum log
See Recovery log.
Quorum resource
The quorum-capable resource selected to maintain the configuration data necessary for recovery of the cluster. This data contains details of all changes that have been applied to the cluster database. The quorum resource is generally accessible to other cluster resources so that any cluster node has access to the most recent database changes.