Managing HP Serviceguard Extension for SAP for Linux, December 2013

5 Clustering SAP Netweaver using SGeSAP packages
5.1 Overview
This chapter describes in detail how to implement a SAP cluster using Serviceguard and Serviceguard
Extension for SAP (SGeSAP). Each task is described with examples.
A prerequisite for clustering SAP by using SGeSAP is that the Serviceguard cluster software
installation must have been completed, and the cluster setup and running.
The minimum software requirements are as follows:
• Serviceguard for providing High Availability (HA)
• SGeSAP for clustering SAP in an HA environment
• NFS toolkit (optional for certain type of installations) for providing NFS services
• Serviceguard Manager for the GUI based setup and configuration of Serviceguard clusters
5.1.1 Three phase approach
A three phase approach is used for clustering the SAP.
1. Setup the infrastructure for SAP installation (SAP pre-installation).
a. Setup of one (or more) sapnfs packages for providing NFS services to all the cluster
nodes.
b. Setting up a base package, also called a tentative package with some selected
Serviceguard and SGeSAP modules. You can use the base package for the initial SAP
instance and database installations.
NOTE: The base package is not a strict requirement, but it allows you to troubleshoot
configuration issues in an early stage in the cluster.
2. Install SAP instances and databases (SAP installation).
3. Complete the package setup (SAP post-installation).
a. Synchronize configuration changes on the primary node with secondary nodes in the
cluster.
b. Add SGeSAP modules and or update attributes to the base packages introduced in step
1b of first phase.
The steps in Phase 2 of this approach are normally performed by a certified SAP Installer, whereas,
the steps in Phase 1 and 3 are performed by a customer service engineer trained in Serviceguard
and SGeSAP.
It is important to categorize the following:
• The volume groups and logical volumes of the SAP or database instances
• The virtual hostnames designated for these instances
• How these are mapped in to Serviceguard packages
Before starting with Phase 1, it is important to determine the volume groups and logical volumes
that belong to the package, and finally it is also important to remember that resources like IP
addresses (derived from the virtual hostnames) and volume groups can only belong to one package.
5.1 Overview 49