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Chapter 2. Overview

This manual provides a step-by-step installation of Oracle for High Availability (HA) using the Red Hat Advanced Platform product, Cluster Suite. This manual provides installation instructions for the following two scenarios:
  • Simple RDBMS Enterprise Edition failover
  • Oracle RDMBS Real Applications Cluster (RAC) on shared GFS file systems
A sample two-node cluster is provided for both installation types. Each installation incorporates best practices that are both common and specific to the chosen method of Red Hat Cluster Suite HA.
The remainder of this chapter describes the components of the sample installation configurations and provides general overviews of the configuration issues an Oracle HA installation must address. It is organized as follows:

Note

Installing Oracle for use with Red Hat Cluster Suite HA is complex and requires close collaboration across the entire IT organization, including development when RAC is deployed. HA computing is a single platform that must span these departments successfully, in order to achieve the intended reliability. The quality of this collaboration cannot be under-estimated.

2.1. Oracle Enterprise Edition HA Components

The first installation scenario this document describes requires Oracle Enterprise Edition HA for Red Hat Cluster Suite. The second installation scenario this document describes requires the Real Application Clusters (RAC) option of Oracle Enterprise edition. The following sections summarize these components and their certification requirements.

2.1.1. Oracle Enterprise Edition HA for Red Hat Cluster Suite

Oracle has supported a simple, exclusive failover, since Oracle7. Customers familiar with HP’s Serviceguard will recognize this Red Hat Cluster Suite HA configuration.
In this configuration, there are two servers that are licensed to run Oracle Enterprise Edition, but only one server may access the database at any given time. Oracle refers to this as single-instance, non-shared operation. Red Hat Cluster Suite ensures isomorphic, or mutually exclusive operation of these two servers. If both servers access the database simultaneously, corruption may result. Red Hat Cluster Suite is responsible for ensuring this does not happen. The Enterprise Edition HA failover case will assume the file system is ext3, but others are supported.
There are no specific certification requirements for combinations of Red Hat Cluster Red Hat Cluster, RHEL file systems and Oracle Enterprise Edition HA. Oracle supports any certified, non-local file system that is supported by Red Hat Cluster Suite. For more information on Oracle HA on Red Hat Cluster Suite, see the kbase article “Red Hat Support for Oracle Enterprise Edition and Cold Failover Cluster Suite configurations”: http://kbase.redhat.com/faq/docs/DOC-21631.

2.1.2. Oracle Real Application Clusters for Red Hat Cluster Suite and GFS

Oracle Enterprise Edition has a separately priced option called Real Application Clusters (RAC), and this does provide for shared access, or multi-instance, shared operation. Red Hat Cluster Suite Oracle RAC is certified only for use with GFS shared volumes.
Although Oracle RAC supports more than eight nodes, most customer deployments are typically four to eight nodes. The mechanics of a multi-node RAC installation can be demonstrated with the same two-node cluster that can be used for Enterprise Edition HA. This provides an equivalent configuration for comparison and to determine which option is best for your requirements.
Oracle RAC has very specific certification requirements that include a minimal update release level of RHEL and a patchset specific version of the Oracle RDBMS RAC kernel. Certified configurations of Oracle RAC with GFS can be found in the Oracle Support document ID 329530.1.
In the RAC configuration described in this document, there are two servers licensed to run Oracle Enterprise Edition simultaneously. This is referred to as shared disk architecture. The database files, online redo logs, and control files for the database must be accessible to each node in the cluster. Red Hat Cluster Suite and Oracle Clusterware work together to ensure the health of the cluster is optimal.