When you restart the SAP instance using command startsap, the program sapstart is automatically called. This program automatically calls the program sapcpe. Program sapcpe takes care of the automatic synchronization of executables and copies them from the central directory into the local directory.
The instance profile manages calls to sapcpe. The following instance parameters are normally set in the profile:
Name of the central directory for executables.
Name of the local directory for executables.
At all subsequent start ups, sapcpe checks that the local executables are still current and copies any new or altered executables from the central directory.
If sapcpe is called from sapstart, it writes all actions to the log file in the local directory
For example: UNIX:/usr/sap/<SAPSID>/<INSTANCE NAME>/work/sapcpe.log.
sapcpe can work with compressed executable files (<file name>.Z) in the central directory.
If you have a large number of distributed R/3 instances (more than 5), SAP recommends storing executables in compressed form in the central directory.
Compressed files reduce the network load caused by copying executables by approximately 50%.
sapcpe detects changes in compressed files using the time stamp. If the compressed file is newer than the local copy, sapcpe copies the compressed file from the central directory to the local directory and decompresses it.
There are no special access authorizations required for sapcpe. Therefore, take the following security precautions:
Do not set the set user ID bit (UNIX systems) for sapcpe authorization.
Since sapcpe is executed as user <SID>adm, certain programs cannot be updated These include programs that belong to root or to another superuser, and also programs that are active when sapcpe updates a local system. If sapcpe encounters ownership or authorization problems, it records the problems in its log file. You must then update the relevant executables manually, or correct the problem and restart the instance.
Usually only programd saposcol (SAP operating system monitor) and icmbnd are affected by this.
Program saposcol is started when the SAP system is started.
If a saposcol (or icmbnd ) error message appears in the sapcpe log, saposcol must be updated.
In this case you have to stop the program, and copy the executable manually from the central executable directory into the local executable directory.
Do not update saposcol by running the program from the central executables directory. The program may terminate abnormally if paging over the network is so slow that it produces time-outs.