Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

■ network addresses of nodes
■ port addresses
When a node joins the cluster, this information is automatically loaded into VxVM
on that node at node startup time.
Note: To make effective use of the cluster functionality of VxVM requires that
you configure a cluster monitor, such as provided by HP Serviceguard, or by GAB
(Group Membership and Atomic Broadcast) in VCS. If HP Serviceguard is used as
the cluster monitor, no additional configuration of VxVM is required, apart from
the cluster configuration requirements of HP Serviceguard.
The cluster monitor startup procedure effects node initialization, and brings up
the various cluster components (such as VxVM with cluster support, the cluster
monitor, and a distributed lock manager) on the node. Once this is complete,
applications may be started. The cluster monitor startup procedure must be
invoked on each node to be joined to the cluster.
For VxVM in a cluster environment, initialization consists of loading the cluster
configuration information and joining the nodes in the cluster. The first node to
join becomes the master node, and later nodes (slaves) join to the master. If two
nodes join simultaneously, VxVM chooses the master. Once the join for a given
node is complete, that node has access to the shared disk groups and volumes.
Cluster reconfiguration
Cluster reconfiguration occurs if a node leaves or joins a cluster. Each node’s
cluster monitor continuously watches the other cluster nodes. When the
membership of the cluster changes, the cluster monitor informs VxVM for it to
take appropriate action.
During cluster reconfiguration, VxVM suspends I/O to shared disks. I/O resumes
when the reconfiguration completes. Applications may appear to freeze for a
short time during reconfiguration.
If other operations, such as VxVM operations or recoveries, are in progress, cluster
reconfiguration can be delayed until those operations have completed. Volume
reconfigurations do not take place at the same time as cluster reconfigurations.
Depending on the circumstances, an operation may be held up and restarted later.
In most cases, cluster reconfiguration takes precedence. However, if the volume
reconfiguration is in the commit stage, it completes first.
See “Volume reconfiguration” on page 466.
See “vxclustadm utility” on page 465.
Administering cluster functionality
Cluster initialization and configuration
464