I have a service that runs every 30 seconds. The systemd timer file for this service is as below:~# cat /etc/systemd/system/speed_check.timer[Unit]Description=Check device speed[Timer]OnBootSec=1OnUnitActiveSec=30[Install]WantedBy=multi-user.targetThe service file simply calls a python script:# cat /etc/systemd/system/speed_check.service [Unit]Description=Check device speed[Service]Type=simpleExecStart=/usr/bin/check-speedEvery 30 seconds, when systemd starts the service, it prints two logs:Jan  8 17:54:23 localhost systemd[1]: Starting Check device speed...Jan  8 17:54:23 localhost systemd[1]: Started Check device speed.Is there a way to suppress these messages? They are filling up my syslog!thanks 
Prevent systemd from writing to syslog each time it starts the same service
systemd
There are several possibilites. You should configure the file /etc/systemd/journald.conf. Two relevant options (from the man page) are:RateLimitInterval=, RateLimitBurst= Configures the rate limiting that is applied to all messages generated on the system. If, in the time interval       defined by RateLimitInterval=, more messages than specified in RateLimitBurst= are logged by a service, all       further messages within the interval are dropped until the interval is over. A message about the number of       dropped messages is generated. This rate limiting is applied per-service, so that two services which log do not       interfere with each other's limits. Defaults to 1000 messages in 30s. The time specification for       RateLimitInterval= may be specified in the following units: s, min, h, ms, us. To turn off any kind of       rate limiting, set either value to 0.andStorage=      Controls where to store journal data. One of volatile, persistent, auto and none. If volatile, journal       log data will be stored only in memory, i.e. below the /run/log/journal hierarchy (which is created if needed).       If persistent, data will be stored preferably on disk, i.e. below the /var/log/journal hierarchy (which is       created if needed), with a fallback to /run/log/journal (which is created if needed), during early boot and if       the disk is not writable.  auto is similar to persistent but the directory /var/log/journal is not created if       needed, so that its existence controls where log data goes.  none turns off all storage, all log data received       will be dropped. Forwarding to other targets, such as the console, the kernel log buffer or a syslog daemon will       still work however. Defaults to auto.Thus you can turn off all syslogs by means of Storage=none, but this seems excessive and unwise. Limiting the rate (the first option= is much wiser; the default is 1000 messages per 30s, which is way above what you wish, and explains why you are having so much output, unchecked. Or, you may use one of these options,    SystemMaxUse=, SystemKeepFree=, SystemMaxFileSize=, RuntimeMaxUse=, RuntimeKeepFree=, RuntimeMaxFileSize=to control the size of journal files stored. You can pair these options with one of these, MaxFileSec=      The maximum time to store entries in a single journal file before rotating to the next oneMaxRetentionSec=      The maximum time to store journal entries.to retain all syslog messages, but for a shorter time. Lastly, you may wish to use:MaxLevelStore=, MaxLevelSyslog=, MaxLevelKMsg=, MaxLevelConsole=, MaxLevelWall=      Controls the maximum log level of messages that are stored on disk, forwarded to syslog, kmsg, the console or       wall (if that is enabled, see above). As argument, takes one of emerg, alert, crit, err, warning,       notice, info, debug or integer values in the range of 0..7 (corresponding to the same levels). Messages       equal or below the log level specified are stored/forwarded, messages above are dropped. Defaults to debug for       MaxLevelStore= and MaxLevelSyslog=, to ensure that the all messages are written to disk and forwarded to syslog.       Defaults to notice for MaxLevelKMsg=, info for MaxLevelConsole= and emerg for MaxLevelWall=.to forgo less important messages, and retain only critical ones. 