root@olive.x83.net# show system syslog | display set
set system syslog archive size 1000k
set system syslog archive files 10
set system syslog archive world-readable
set system syslog user * any emergency
set system syslog file messages any notice
set system syslog file messages authorization info
set system syslog file interactive-commands interactive-commands any
set system syslog file security authorization any
set system syslog file security interactive-commands any
set system syslog console authorization info

To stop recording system messages :

deactivate system syslog file messages

and to start recording :

activate system syslog file messages

To turn of logging :

delete system syslog file messages