1.2. Red Hat Cluster Suite Introduction

Red Hat Cluster Suite (RHCS) is an integrated set of software components that can be deployed in a variety of configurations to suit your needs for performance, high-availability, load balancing, scalability, file sharing, and economy.

RHCS consists of the following major components (refer to Figure 1-1):

• Cluster infrastructure — Provides fundamental functions for nodes to work together as a cluster: configuration-file management, membership management, lock management, and fencing.

• High-availability Service Management — Provides failover of services from one cluster node to another in case a node becomes inoperative.

• Cluster administration tools — Configuration and management tools for setting up, configuring, and managing a Red Hat cluster. The tools are for use with the Cluster Infrastructure components and with the High-availability and Service Management components.

• Linux Virtual Server (LVS) — Routing software that provides IP-Load-balancing. LVS runs in a pair of redundant servers that distributes client requests evenly to real servers that are behind the LVS servers.

You can supplement Red Hat Cluster Suite with the following components, which are part of an optional package (and not part of Red Hat Cluster Suite):

• Red Hat GFS (Global File System) — Provides a cluster file system for use with Red Hat Cluster Suite. GFS allows multiple nodes to share storage at a block level as if the storage were connected locally to each cluster node.

• Cluster Logical Volume Manager (CLVM) — Provides volume management of cluster storage.

• Global Network Block Device (GNBD) — An ancillary component of GFS that exports block-level storage to Ethernet. This is an economical way to make block-level storage available to Red Hat GFS.

For a lower level summary of Red Hat Cluster Suite components, refer to Chapter 2 Red Hat Cluster Suite Component Summary.