Pre-Installation Considerations

Before you install the SAP software, see "Installing and Configuring SAP and the Database", and consider the following cluster-related issues.

• Install SAP binaries and SAP users' home directories - Install SAP binaries and users' home directories on the cluster file system. Installation on the cluster file system, however, has some drawbacks with SAP software release upgrades. See "Determining the Location of the Application Binaries" for information about drawbacks.

• After you create all of the file systems for the database and for SAP, create the mount points, and put the mount points in the /etc/vfstab file on all of the cluster nodes - See the SAP installation guides, Installation of the SAP R/3 on UNIX and R/3 Installation on UNIX-OS Dependencies, for details on how to set up the database and SAP file systems.

• Create the required groups and users on all of the cluster nodes - Create the required groups and users for the SAP software on all of the cluster nodes according to the SAP installation guides, Installation of the SAP R/3 on UNIX and R/3 Installation on UNIX-OS Dependencies.

• Configure Sun Cluster HA for NFS on the cluster that hosts the central instance if you plan to install some external SAP application servers - See "Installing and Configuring Sun Cluster HA for NFS" for details on how to configure Sun Cluster HA for NFS.

• Set up the /etc/nsswitch.conf file so that the data service starts and stops correctly during switchovers or failovers - On each node that can master the logical host that runs Sun Cluster HA for SAP, the /etc/nsswitch.conf file must have one of the following entries for group.

  group: group: files group: files [NOTFOUND=return] nis group: files [NOTFOUND=return] nisplus

  Sun Cluster HA for SAP uses the su user command to start and stop the database node. The network information name service might become unavailable when a cluster node's public network fails. Adding the preceding entries for group ensures that the su(1M) command does not refer to the NIS/NIS+ name services if this unavailability occurs.