tcpdump can create a new log file every couple of bytes, it can also
be asked to limit the number of logfiles and wraps the counter back to
zero, and at least tcpdump 4.1 can also compress the log file with an
external script. Create a start script around this feature to log to
a given directory but not use more space than allowed to. The script
was created by Jan Luebbe and then modified.
Holger Hans Peter Freyther