To make sure the system was alive at that time, syslog periodically writes such messages to /var/log/messages: Sep 19 22:09:27 debian -- MARK -- Sep 19 22:29:27 debian -- MARK -- Sep 19 22:49:27 debian -- MARK -- How is it possible to adjust the frequency of such entries? I'd like to make it less frequent than 20 minutes. Cheers -A