Managing Serviceguard Extension for SAP, December 2007

Planning the Storage Layout
SAP Instance Storage Considerations
Chapter 2 53
In clustered SAP environments that use the startsap mechanism it is
required to install local executables. Local executables help to prevent
several causes for package startup or package shutdown hangs due to
the unavailability of the centralized executable directory. Availability of
executables delivered with packaged SAP components is mandatory for
proper package operation. History has shown that it is a good practice to
create local copies for all files in the central executable directory. This
includes shared libraries delivered by SAP.
NOTE SGeSAP packages and service monitors require SAP tools. Patching the
SAP kernel sometimes also patches SAP tools. Depending on what SAP
changed, this might introduce additional dependencies on shared
libraries that weren’t required before the patch. Depending on the
SHLIB_PATH settings of the root user it might no longer be possible for
SGeSAP to execute the SAP tools after applying the patch. The
introduced additional libraries are not found. Creating local copies of the
complete central executable directory prevents this issue.
To automatically synchronize local copies of the executables, SAP
components deliver the sapcpe mechanism. With every startup of the
instance, sapcpe matches new executables stored centrally with those
stored locally.