logfile_max_size

Specifies the recommended maximum log file size before the log file is rotated. Set to 0 to specify no limit. Use KB, MB, or GB for units (if no units are specified, the file size is assumed to be in bytes). 

logfile_max_size = size [KB|MB|GB]

The server periodically checks the size of the current log file. If it is greater than the specified size, the file is copied to a backup and then emptied. The server then begins writing to the empty log file until it reaches the specified size again.

Backup log files are named sequentially and stored in the same directory as the current log.