Managing Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64), February 2008

Planning a File System Layout for SAP in a Serviceguard/LX Cluster Environment
About Impacted File Systems
Chapter 2 47
About Impacted File Systems
In an SAP environment, the storage, the file system layout and the
mount points of the SAP system and the Database instance are key for
configuring a Serviceguard cluster.
The file systems are key because of the separation task of the file
systems required: which file systems can be shared between cluster
nodes and which file systems cannot. This requires some understanding
of how the file systems are used within an SAP configuration. It is
important to describe the application itself, the environment it runs in
and its components. These could be: processes, IP addresses, storage, file
systems, mount points, configuration profiles.
About Storage Options
For each of the above listed file system scenarios the following questions
need to be answered:
1. Whether it needs to be kept as a LOCAL copy on internal disks of
each node of the cluster. The file system requires a LOCAL mount
point.
2. Which of the file systems have to be SHARED by all cluster nodes on
a SAN storage, but have to be mounted in (SHARED EXCLUSIVE)
mode by the cluster node that the SAP instance failed over to and
will run that instance.
3. Which of the file systems can be SHARED in (SHARED NFS) mode
in the cluster by all cluster nodes (e.g. access to the file system is
required from more than one cluster node at the same time)?