i am using a Ubuntu Server as a NTP Server, it's working very well, the clock is synchronised.
now i am trying to activate Logs so i can see "Clients" that synchronize with my server.

i added two lines to my config :
logfile /var/log/ntpd.log
statsdir /var/log/ntpstats/

the second one : "statsdir" give informations just about external servers with whom my server synchronize it's clock, it's not the informations i am seeking

even after restarting my daemon, when i check the "/var/log" directory i cannot find the file ntpd.log, i wonder why ?
is it the correct line to add to activate logs ?
such file /var/log/ntpd.log, will it contain informations about NTP clients ?

Thank you so much