I have an Oracle 8.0.4 database running on Windows NT. There are two redo log groups with size of 5M for each redo log. Ever since the creation of the database, there has been inconsistent archive logs generated. Some with the same size of redo logs, many of them with very small size like 500 bytes. It is a development database with very light activity.
There's two possiblities why you may be getting log files that are not close to 5M:
1. an "alter system swith logfile" command is being executed.
2. You have a redo log file out there that is not sized to 5M.