I found at my /var/log/syslog:

syslog-ng[4102]: Internal error, duplicate configuration elements refer to the same persistent config; name=’affile_dd_writers(/dev/tty12)’

So I checked my /etc/syslog-ng/syslog-ng.conf and I found that:

$ grep ‘/dev/tty12′ /etc/syslog-ng/syslog-ng.conf
destination kern { file(”/var/log/kern.log”); file(”/dev/tty12″); };
destination console_all { file(”/dev/tty12″); };

After reading docs, I didn’t find any destination having 2 files entries. Great It looks like a typo. So I made some changes (a easy one):

$ diff /etc/syslog-ng/syslog-ng.conf.bak /etc/syslog-ng/syslog-ng.conf
35c35,36
< destination kern { file(”/var/log/kern.log”); file(”/dev/tty12″); };
—
> destination kern { file(”/var/log/kern.log”); };
> destination kern { file(”/dev/tty12″); };

Ok, got it working again.