Installation guide

6.3 Shared Root and Shared Storage with GFS

6.3.1 SAP Architecture

Following the established SAP documentation is highly recommended:

 SAP Installation Guide

http://service.sap.com/instguides

 SAP Technical Infrastructure Guide

https://www.sdn.sap.com/irj/sdn/ha

6.3.2 SAP Virtual IP Addresses

SAP NetWeaver is typically installed via the graphical installation tool sapinst. Before

beginning the installation, determine which IP addresses and host names are preferred for

use during the SAP installation. First, each node requires a static IP address and an

associated host name. This address is also referred to as the physical IP address . Second,

each database and SAP instance will require a virtual IP address / host name. The virtual

addresses must not be configured at the operating system level because they are under the

control of RHCS. Those addresses are referred to as the virtual IP addresses.

Local dialog instances, which are not part of the cluster, use a virtual host name as an alias to

the physical host name so those SAP instances are not failed over by RHCS.

The enqueue replication instances do not need IP addresses because no connections are

established with them. The virtual host name is only used to start the instances manually via

the sapstart command and to distinguish their profile names from physical host names.

Edit the /etc/hosts file on all nodes and add the virtual host names and their associated IP

addresses. Additionally, add any other cluster relevant host name and address (e.g., the

physical host names or addresses of the nodes) to /etc/hosts so that the DNS server is no

longer a possible single point of failure.

6.3.3 SAP File Systems

The file systems for our scenario must be prepared before installing SAP NetWeaver.

File systems must be set up on shared root, on GFS shared storage, and on a highly

available NFS server.

6.3.3.1 File Systems on Shared Root

File systems such as /usr/sap, /sapmnt and /home can be created on shared root.

6.3.3.2 Shared Storage File Systems

By using GFS as file system for SAP and database instances, the directory /usr/sap/<SID>

and each deeper directory can be a GFS mount point.