Managing Serviceguard Extension for SAP Version B.05.10, September 2010

The table can be used to document used device minor numbers. The device minor numbers of
logical volumes need to be identical for each distributed volume group across all cluster nodes.
If you have more than one system, place /usr/sap/put on separate volume groups created on
shared drives. The directory should not be added to any package. This ensures that they are
independent from any SAP WAS system and you can mount them on any host by hand if needed.
Option 3: SGeSAP CFS Cluster
SGeSAP supports the use of HP Serviceguard Cluster File System for concurrent shared access.
CFS is available with selected HP Serviceguard Storage Management Suite bundles. CFS replaces
NFS technology for all SAP related file systems. All related instances need to run on cluster nodes
to have access to the shared files.
SAP related file systems that reside on CFS are accessible from all nodes in the cluster. Concurrent
reads or writes are handled by the CFS layer. Each required CFS disk group and each required
CFS mount point requires a Serviceguard multi-node package. SGeSAP packages are Serviceguard
single-node packages. Thus, a package cannot combine SGeSAP and CFS related functionality.
Common Directories that are Kept Local
Most common file systems reside on CFS, but there are some directories and files that are kept
local on each node of the cluster:
• /etc/cmcluster —the directory where Serviceguard keeps configuration files and the
node-specific package runtime directories.
• /home/<sid>adm —the home directory of the SAP system administrator with node-specific
startup log files.
• /usr/sap/tmp — the directory where the SAP operating system collector keeps monitoring
data of the local operating system.
• /usr/sap/<SID>/SYS/exe/run—optional directory for usage with sapcpe, i.e. a local
copy of executables (optional for kernel 7.x and higher).
• /usr/sap/hostctrl—the directory where SAP control services for the local host are kept
(kernel 7.x and higher).
• Depending on database vendor and version, it might be required to keep local database
client software. Details can be found in the database sections below.
Content of the local group of directories must be synchronized manually between all nodes of
the cluster. An exception is the optional local directory for SAP executables
/usr/sap/<SID>/SYS/exe/run. This directory is automatically synchronized as part of every
instance startup and shutdown operation. A symbolic link called
/usr/sap/<SID>/SYS/exe/ctrun needs to be created to access the centrally shared location.
Directories that Reside on CFS
The following table shows a recommended example on how to design SAP file systems for CFS
shared access.
Table 2-5 File System Layout for SGeSAP CFS Clusters
DG NamePackage Name ExampleAccess PointMount Point
SG-CFS-DG-<NR1>SG-CFS-MP-<NR1>
shared disk and
CFS
/sapmnt/<SID>
SG-CFS-DG-<NR2>SG-CFS-MP-<NR2>/usr/sap/trans
SG-CFS-DG-<NR1>SG-CFS-MP-<NR3>/usr/sap/<SID>
The table can be used to document used volume or disk groups across all cluster nodes.
28 Planning the Storage Layout