10 Cluster Administration; Cluster Overview; Multi-Node Support Beyond Two Nodes - HP ProLiant 300 Series Administration Manual

10 Cluster Administration

NOTE:
Not all HP ProLiant Storage Servers can be clustered. Refer to the HP ProLiant Storage Server QuickSpecs
to determine if your storage server can be clustered.
One important feature of the HP ProLiant Storage Server clusterable models is that they can operate as a
single node or as a cluster. This chapter discusses cluster installation and cluster management issues.

Cluster overview

Two server nodes can be connected to each other and deployed as a no single point of failure (NSPOF)
dual redundant cluster. The nodes are connected by a crossover cable and are each connected to
network switches or hubs. This connection allows communication between the nodes to track the state
of each cluster node. Each node sends out periodic messages to the other node; these messages are
called heartbeats. If a node stops sending messages, the cluster service fails over any resources that
the node owns to the other node. For example, if the node that owns the Quorum disk is shut down
for any reason, its heartbeat stops. The other node detects the lack of the heartbeat and takes over
ownership of the Quorum disk and the cluster.

Multi-node support beyond two nodes

Clusterable storage server devices may be deployed in multi-node clustering beyond two nodes. Refer
to the associated Storage Array documentation to determine the number of nodes supported by the
array under Windows Storage Server 2003. While the discussion presented in this guide addresses
only two nodes, additional nodes may be added into the cluster. Considerations for additional fiber
path connections and the private network should be made. In the case of the private network, a hub or
switch is required since the cross over cable is no longer applicable.
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