VERITAS Volume Manager 4.1 Administrator's Guide

Administering Cluster Functionality

Overview of Cluster Volume Management

Chapter 10 353

joining or leaving the cluster, and which have failed. The private network

requires at least two communication channels to provide redundancy

against one of the channels failing. If only one channel were used, its

failure would be indistinguishable from node failure—a condition known

as network partitioning.

Figure 10-1 Example of a 4-Node Cluster

To the cluster monitor, all nodes are the same. VxVM objects conﬁgured

within shared disk groups can potentially be accessed by all nodes that

join the cluster. However, the cluster functionality of VxVM requires that

one node act as the master node; all other nodes in the cluster are

slave nodes. Any node is capable of being the master node, and it is

responsible for coordinating certain VxVM activities.

Redundant

SCSI or Fibre

Channel

Connectivity

Cluster-Shareable

Disks

Redundant Private Network

Node 0

(master)

Node 1

(slave)

Node 2

(slave)

Node 3

(slave)

Cluster-Shareable

Disk Groups