Managing Serviceguard Extension for SAP on Integrity Linux, December 2005

Understanding Serviceguard Extension for SAP on Integrity Linux
Overview of SGeSAP on Integrity Linux
Chapter 112
Two-Package Configuration Model
If you are planning to distribute the database and central instance
between two nodes, use the two-package model. The SAP functionality is
separated into two Serviceguard packages, one for the database (DB) and
the other for the SAP central instance (CI). The database package
contains the filesystems for the NFS mount points.
During normal operation, backup nodes can be used as idle standby, or
various kinds of SAP instances like SAP central instances or
application servers, SAP development systems or SAP test systems. The
shutdown or restart of any number of application servers and SAP
instances as part of the package failover is supported. Multi-instance
SAP systems are allowed inside a cluster. The number of cluster nodes
can be chosen according to the current limitations of Serviceguard for
Linux for Integrity.
The cluster can be configured so that two nodes back up each other, or so
that one or more dedicated hosts back up the nodes running the SAP
packages as illustrated in Figure 1-2.