systemd - excessive syslog messages when users log in over ssh

Question

Every time someone connects with SSH, systemd prints this to the syslog:

Jan 21 09:53:54 server systemd[1]: Created slice User Slice of UID 1002.
Jan 21 09:53:54 server systemd[1]: Starting User Runtime Directory /run/user/1002...
Jan 21 09:53:54 server systemd[1]: Started User Runtime Directory /run/user/1002.
Jan 21 09:53:54 server systemd[1]: Starting User Manager for UID 1002...
Jan 21 09:53:55 server systemd[16973]: Listening on GnuPG cryptographic agent and passphrase cache.
Jan 21 09:53:55 server systemd[16973]: Reached target Paths.
Jan 21 09:53:55 server systemd[16973]: Listening on GnuPG cryptographic agent and passphrase cache (access for web browsers).
Jan 21 09:53:55 server systemd[16973]: Reached target Timers.
Jan 21 09:53:55 server systemd[16973]: Listening on GnuPG network certificate management daemon.
Jan 21 09:53:55 server systemd[16973]: Listening on GnuPG cryptographic agent and passphrase cache (restricted).
Jan 21 09:53:55 server systemd[16973]: Listening on GnuPG cryptographic agent (ssh-agent emulation).
Jan 21 09:53:55 server systemd[16973]: Reached target Sockets.
Jan 21 09:53:55 server systemd[16973]: Reached target Basic System.
Jan 21 09:53:55 server systemd[16973]: Reached target Default.
Jan 21 09:53:55 server systemd[16973]: Startup finished in 81ms.
Jan 21 09:53:55 server systemd[1]: Started User Manager for UID 1002.

This is excessive and unhelpful. How can I disable some of these messages?

I've seen people filtering them out by string matching, but that's just a hack. Surely there should be a verbosity setting somewhere? It's not clear which program is responsible though - is it systemd? ssh? Something else?

Answer 1

As root, try installing an override to the system service

systemctl edit sshd.service

or edit the distribution file

vi /etc/systemd/system/sshd.service

In the former case, you just need to add the overridden directive

[Service]
LogLevelMax=4

If editing the whole file, you will find the entire Service recipe

[Service]
EnvironmentFile=-/etc/default/ssh
ExecStartPre=/usr/sbin/sshd -t
ExecStart=/usr/sbin/sshd -D $SSHD_OPTS
ExecReload=/usr/sbin/sshd -t
ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
RestartPreventExitStatus=255
Type=notify
RuntimeDirectory=sshd
RuntimeDirectoryMode=0755

to which you'll add the LogLevelMax directive.

(log level goes from 0 - emergency - to 6 - debug chatter).

At this point you reload the config and restart the service:

systemctl daemon-reload
systemctl restart sshd.service