Syncthing is a great piece of Software to keep multiple PCs – and tablets – in sync. Unfortunately, it produces a LOT of log spam; on my Ubuntu machines, more than half of the entries in /var/log/syslog are useless syncthing INFO messages.

Here’s how they get produced:

• Syncthing outputs stuff on stdout/stderr
• Systemd, which starts syncthing, connects that stdout and stderr to itself, and sends everything it gets to rsyslogd
• Rsyslogd has a default config to send pretty much everything to /var/log/syslog

And here’s how to change that:

Create a file /etc/rsyslog.d/30-syncthing.conf:


# Ignore syncthing INFO messages
if $programname == 'syncthing' and $syslogseverity-text == 'info' then stop


Restart rsyslogd:
systemctl restart rsyslog

Done!