VERITAS Storage Foundation 4.1 Cluster File System HP Serviceguard Storage Management Suite Extracts, December 2005

CVM Administration

Introduction

Note See the VERITAS Volume Manager Adminstrator’s Guide for complete information on

VxVM and CVM. Online versions of the VxVM documentation set are installed

under the /opt/VRTSvmdoc directory.

A cluster consists of a number of hosts or nodes that share a set of disks. The main benefits

of cluster configurations are:

◆ Availability—If one node fails, the other nodes can still access the shared disks. When

configured with suitable software, mission-critical applications can continue running

by transferring their execution to a standby node in the cluster. This ability to provide

continuous uninterrupted service by switching to redundant hardware is commonly

termed failover.

Failover is transparent to users and high-level applications for database and

file-sharing. You must configure cluster management software, such as HP Serviceguard

to monitor systems and services, and to restart applications on

another node in the event of either hardware or software failure. Serviceguard also allows you

to perform general administration tasks such as making nodes join or leave a cluster.

◆ Off-host processing—Clusters can reduce contention for system resources by

performing activities such as backup, decision support and report generation on the

more lightly loaded nodes of the cluster. This allows businesses to derive enhanced

value from their investment in cluster systems.

The cluster functionality (CVM) of VERITAS Volume Manager (VxVM) allows up to 4

nodes in a cluster to simultaneously access and manage a set of disks under VxVM control

(VM disks). The same logical view of disk configuration and any changes to this is

available on all the nodes. When the cluster functionality is enabled, all the nodes in the

cluster can share VxVM objects. This chapter discusses the cluster functionality that is

provided with VxVM.