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, “Red Hat Cluster Suite Introduction”):
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Cluster infrastructure — Provides fundamental functions for nodes to work together as a cluster: configuration-file management, membership management, lock management, and fencing.
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High-availability Service Management — Provides failover of services from one cluster node to another in case a node becomes inoperative.
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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.
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Cluster Logical Volume Manager (CLVM) — Provides volume management of cluster storage.
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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.
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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, the High-availability and Service Management components, and storage. You can configure and manage other Red Hat Cluster Suite components through tools for those components.
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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.
For a lower level summary of Red Hat Cluster Suite components, refer to Chapter 2, Red Hat Cluster Suite Component Summary.
