Control log file change

Local logs are held in a single circular file. When a file becomes full, the system starts writing messages again from the file's beginning, overwriting old messages.

A central log is written in two files:

When the current file reaches the maximum length specified in the system profile, the system performs a log switch, overwriting the old log file with the current one and starting a new current log file.

To control central log switching, set the parameter rslg/max_diskspace/central to the maximum combined length of the current and old central logs.

Set the parameter in the system in which the central log resides. The system switches log files when the size of the currently active log file reaches approximately half of size that you specified for the length parameter.

Since the switching of logs is controlled by a length parameter, you can roughly control the time period to be covered by a system log.

Setting a high file length value will cause the two log files to record events over a lengthy period of time under normal conditions. A high value can also help prevent lost messages in the central log in the event that sudden heavy message activity causes rapid switching of the central log.


In a log switch, the system renames the current log to the old file, overwriting the old file.

No message is issued before an old log is erased.

If you wish to archive old messages, you will nedd to provide a facility for this.