Displays unit files list of the systemd init process:
sudo systemctl list-unit-files
Displays a list of services that could not be run while system startup:
sudo systemctl --state=failed
Displays detailed information about specified service:
sudo systemctl status mysql.service
Stops specified service:
sudo systemctl stop mysql
Starts specified service:
sudo systemctl start mysql
Kills all processes that belongs to specified service:
sudo systemctl kill mysql
Sends SIGHUP signal to the test process of specified service:
sudo systemctl kill -s HUP --kill-who=test mysql
Makes a specified service not to run during system startup:
sudo systemctl disable mysql
Makes a specified service to run during system startup:
sudo systemctl enable mysql
To run a custom script (here: /usr/local/bin/firewall.sh) during system startup, first we need to create a unit file for the script, for ex.: /lib/systemd/system/firewall.service with the following content:
# iptables firewall service file
[Unit]
Description=Iptables firewall and fwsnort rules
After=network.target
After=syslog.target
[Install]
WantedBy=multi-user.target
[Service]
User=root
Group=root
ExecStart=/usr/local/bin/firewall.sh
sudo systemctl enable firewall
Displays load time stats for all services being run at the system startup (both kernel and user space):
systemd-analyze
Displays load time stats for all services being run:
systemd-analyze blame
Generates a load time stats plot for all services:
systemd-analyze plot >plot.svg
View created plot with eye of gnome application:
eog plot.svg
Displays system journal messages since last system startup:
sudo journalctl
Displays system journal error messages since last system startup:
sudo journalctl -b -p err
Displays system journal messages since specified period:
sudo journalctl --since=yesterday
sudo journalctl --since=2016-05-28
Displays system journal messages within specified time period:
sudo journalctl --since=2016-05-27 --until=2016-05-29
Displays system journal messages generated by given service (mysql) within specified time period:
sudo journalctl -u mysql --since=yesterday --until=now
Displays all systemd services/units which system journal messages can be filtered for:
sudo journalctl -F _SYSTEMD_UNIT
Displays all metadata that was registered ever:
sudo journalctl -o verbose -n
Filters system journal messages for specified metadata (here: _UID and _EXEC) and its values:
sudo journalctl _UID=0 _EXE=/usr/sbin/thermald