[systemd-devel] How to silence systemd's "Starting", "Succeeded" and "Started" notifications?

[Jaime]

I have a simple non-looping shell script that I call every 60 seconds
using a systemd service and associated timer. My shell script produces
no output at all. My journal looks like this:

May 15 03:43:00 server systemd[450]: Starting updater.service...
May 15 03:43:01 server systemd[450]: updater.service: Succeeded.
May 15 03:43:01 server systemd[450]: Started updater.service.
May 15 03:44:00 server systemd[450]: Starting updater.service...
May 15 03:44:01 server systemd[450]: updater.service: Succeeded.
May 15 03:44:01 server systemd[450]: Started updater.service.
May 15 03:45:00 server systemd[450]: Starting updater.service...
May 15 03:45:01 server systemd[450]: updater.service: Succeeded.
May 15 03:45:01 server systemd[450]: Started updater.service.
May 15 03:46:00 server systemd[450]: Starting updater.service...
May 15 03:46:01 server systemd[450]: updater.service: Succeeded.
May 15 03:46:01 server systemd[450]: Started updater.service.
May 15 03:47:00 server systemd[450]: Starting updater.service...
May 15 03:47:01 server systemd[450]: updater.service: Succeeded.
May 15 03:47:01 server systemd[450]: Started updater.service.
May 15 03:48:00 server systemd[450]: Starting updater.service...
May 15 03:48:01 server systemd[450]: updater.service: Succeeded.
May 15 03:48:01 server systemd[450]: Started updater.service.

Is it possible to stop these notification lines from being entered
into the journal? I understand that one alternative is to just rewrite
the script to loop forever ("while true ; do blah ; done"-style) and
get rid of the timer, but I wanted to know whether there is any
built-in log-level style control for these systemd-generated messages.

Thanks.