Dell PowerVault 775N (Rackmount NAS Appliance) - Manual (Page 78)

Table 7-3. Resources and Configurable Parameters
Resource Configurable Parameters
File share Share permissions and number of simultaneous users
Share name (clients will detect the name in their browse or explore lists)
Share comment
Shared file path
IP address IP address
Subnet mask
Network parameters for the IP address resource (specify the correct cluster network)
Network name System name
Physical disk Drive for the physical disk resource (the drive cannot be changed after the resource is created)
Quorum Resource
The quorum resource is a common resource in the cluster that is accessible by all of the cluster nodes. Normally a physical
disk on the shared storage, the quorum resource maintains data integrity, cluster unity, and cluster operations—such as
forming or joining a cluster—by performing the following tasks:
Enables a single node to gain and defend its physical control of the quorum resource — When the cluster is
formed or when the cluster nodes fail to communicate, the quorum resource guarantees that only one set of active,
communicating nodes is allowed to form a cluster.
Maintains cluster unity — The quorum resource allows cluster nodes that can communicate with the node containing
the quorum resource to remain in the cluster. If a cluster node fails for any reason and the cluster node containing the
quorum resource is unable to communicate with the remaining nodes in the cluster, MSCS automatically shuts down the
node that does not control the quorum resource.
Stores the most current version of the cluster configuration database and state
data — If a cluster node fails, the configuration database helps the cluster recover a failed resource or recreate the
cluster in its current configuration.
The physical disk is the only type of resource supported by the NAS cluster solution that can act as a quorum resource.
NOTE: The Majority Node Set Quorum resource type is not supported.
Using the Quorum Resource for Cluster Integrity
The quorum resource is also used to ensure cluster integrity by performing the following functions:
Maintaining the cluster node database
Ensuring cluster unity
When a node joins or forms a cluster, the Cluster Service must update the node's private copy of the cluster database. When
a node joins an existing cluster, the Cluster Service can retrieve the data from the other active nodes. However, when a node
forms a cluster, no other node is available. The Cluster Service uses the quorum resource's recovery logs to update the node's
cluster database, thereby maintaining the correct version of the cluster database and ensuring that the cluster is intact.
For example, if node 1 fails, node 2 continues to operate, writing changes to the cluster database. Before you can restart
node 1, node 2 fails. When node 1 becomes active, it updates its private copy of the cluster database with the changes made
by node 2 using the quorum resource's recovery logs to perform the update.