how to prevent cron logs from registering in syslog?

Solution 1:

You need to find the line that defines what should be sent to /var/log/syslog and modify it so that cron messages are not included. For example on an Ubuntu system I have to hand the /etc/rsyslog.d/50-default.conf file has the following entry for syslog:

*.*;auth,authpriv.none             -/var/log/syslog

changing it to:

*.*;cron,auth,authpriv.none             -/var/log/syslog

Does what you want. Note that the above is taking advantage of the ability to specify multiple facilities with the same priority as a list, if you don't already have a .none priority you would have to do this for example:

*.*;auth,authpriv.info;cron.none             -/var/log/syslog