HP Serviceguard Extension for SAP (SGeSAP) manual Database Instance Storage Considerations

requires a Serviceguard multi-node package. SGeSAP packages are Serviceguard single-node packages. Thus, a package can not 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 in which Serviceguard keeps its 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 in which 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 in which SAP control services for the local host are kept (kernel 7.x and higher)

•Depending on database vendor and version, it might in addition 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. It gets 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

Mount Point	Access Point	Package Name Example	DG Name
/sapmnt/<SID>	shared disk and CFS SG-CFS-DG-<NR1>SG-CFS-MP-<NR1>
/usr/sap/trans		SG-CFS-DG-<NR2>SG-CFS-MP-<NR2>
/usr/sap/<SID>		SG-CFS-DG-<NR1>SG-CFS-MP-<NR3>

The table can be used to document used volume or disk groups across all cluster nodes.

The /usr/sap/tmp might or might not be part of the local root file system. This is the working directory of the operating system collector process saposcol. The size of this directory will rarely be beyond a few Megabytes.

Database Instance Storage Considerations

SGeSAP internally supports clustering of database technologies of different vendors. The vendors have implemented individual database architectures. The storage layout for SGeSAP cluster environments needs to be discussed individually for each:

•Oracle Single Instance RDBMS

•Oracle Real Application Clusters

•MAXDB Storage Considerations

26 Planning the Storage Layout