HP Veritas Volume Manager 5.0 -UX 11i v3 manual Overview of cluster volume management

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Administering cluster functionality

Overview of cluster volume management

enabled, all the nodes in the cluster can share VxVM objects such as shared disk groups. Private disk groups are supported in the same way as in a non-clustered environment. This chapter discusses the cluster functionality that is provided with VxVM.

Note: You need an additional license to use this feature.

This chapter does not discuss Veritas Storage Foundation Cluster File System (SFCFS) nor cluster management software such as Veritas Cluster Server (VCS). Such products are separately licensed, and are not included with Veritas Volume Manager. See the documentation provided with those products for more information about them.

For information about administering a cluster that is under the control of HP Serviceguard, refer to the HP Serviceguard Storage Management Suite documentation.

For additional information about using the Dynamic Multipathing (DMP) feature of VxVM in a clustered environment, see “DMP in a clustered environment” on page 132.

For information about administering campus cluster configurations (also known as stretch cluster or remote mirror configurations), see “Administering sites and remote mirrors” on page 431.

Overview of cluster volume management

In recent years, tightly-coupled cluster systems have become increasingly popular in the realm of enterprise-scale mission-critical data processing. The primary advantage of clusters is protection against hardware failure. Should the primary node fail or otherwise become unavailable, applications can continue to run by transferring their execution to standby nodes in the cluster. This ability to provide continuous availability of service by switching to redundant hardware is commonly termed failover.

Another major advantage of clustered systems is their ability to reduce contention for system resources caused by activities such as backup, decision support and report generation. Businesses can derive enhanced value from their investment in cluster systems by performing such operations on lightly loaded nodes in the cluster rather than on the heavily loaded nodes that answer requests for service. This ability to perform some operations on the lightly loaded nodes is commonly termed load balancing.

The cluster functionality of VxVM works together with the cluster monitor daemon that is provided by VCS or by the host operating system. When configured correctly, the cluster monitor informs VxVM of changes in cluster