The System Log

The SAP System logs all system errors, warnings, user locks due to failed logon attempts from known users, and process messages in the system log. There are to two different types of logs created by the system log:

·  Local Logs

·  Central Logs

Use transaction SM21 to access the system log output screen. With this transaction, you can read any of the messages that are contained in the system logs. You can modify the view to meet your needs.

Local Logs

Each SAP System application server has a local log that receives all the messages output by this server. The system log records these messages in a circular file on the server. When this log file reaches the maximum permissible length, the system log overwrites it, starting over from the beginning. (The location of the local log is specified in the rslg/local/file profile parameter.)

Central Logs

We recommend that you also maintain a central log file on a selected application server. Each individual application server then sends its local log messages to this server. The server that you designate to maintain the central log collects the messages from the other application servers and writes these messages to the central log.

The central log consists of two files: the active file and the old file. (The location of the active file is specified in the rslg/central/fileprofile parameter; the location of the old file is specified in the rslg/central/old_file.)

The active file contains the current log. When it reaches the maximum size, the system performs a "log file switch". It deletes the old log file, makes the previously active file the “old” file, and creates a new active file. The switch occurs when the size of the active log file is half the value as specified in the rslg/max_diskspace/central parameter. (Note: the SAP System does not support the saving of old system log files. If you want to save old logs, then you must archive them yourself.)