System events are stored in SYSLOGDT.FCS and SYSLOGIX.FCS which are c-tree ISAM files. When a server is starting and automatic recovery occurs involving Restore Points, a ctSYSLOGrstpntRECOVERY event is logged. However, if a startup error occurs, the server comes down before the SYSLOG files are available. In this case, the events are stored in a temporary event file named EVENT_DT.FCS. This file is almost identical to SYSLOGDT.FCS. The difference is that each record starts with the log position of the last checkpoint. This information is used in subsequent processing of the temporary event file. This file is created if needed, and typically does not exist.
Once a server makes a successful start, it checks for the temporary event file, reads each record in physical order, and if the starting checkpoint for recovery agrees with the checkpoint location stored in the EVENT_DT.FCS record, the event is added to the SYSLOG files. At the end of reading all records, the event file is renamed to the following (where the date and time correspond to the system time when the temporary file is renamed):
The reason more than one record may exist in the temporary event file is that successive failed startups will each contribute a record until the server startup is successful, at which time it is renamed. The renamed files are not used by the server, but they are available for archival purposes.