Hi,

Depending on you OS ( please, always post your platform on every question, even if you think that it's not necessary ), there're some tools to do log rotation... logrotate ( linuxes ), logadm ( solaris ), etc... keep in mind that everytime you change a file that is modified by syslog, you must restart the daemon... you can do it in a lots of ways, restarting the service on the initialization scripts, sending a HUP signal to the process ( it works on every *IX "flavour" ), etc...