systemd
Table of Contents
1. systemctl
1.1. List
1.1.1. Services
systemctl # runnning systemctl --failed # failed
1.1.2. Units
systemctl list-units # add filters if required (--all, --state, --type) systemctl --state help # show state filters systemctl --type help # show type filters
1.1.3. Others
systemctl list-dependencies <unit> # list dependencies of a unit
1.2. Operations
1.2.1. Common operations
systemctl {start,restart,reload,stop,status,enable,disable} foo.service
1.2.2. Debug operations
systemctl edit [unit] systemctl show [unit] # list properties systemctl cat [unit] # list file
1.2.3. Restart
systemctl reset-failed [service_name] # reset failed restart systemctl daemon-reload # reload daemons after unit file changes
1.3. User services
cat /usr/lib/systemd/user/emacs.service systemctl --user status emacs.service # without --user this won't be shown
2. journalctl
2.1. Filters
journalctl -u [unit] -b # for some unit, for the most recent boot journalctl -p 3 -b # list errors(see -p flag) of current boot journalctl -rb -1 # Show logs of last boot in reverse order journalctl -b # Show logs of last boot in reverse order journalctl -f # follow log (like tail -f) journalctl --since=2012-10-15 --until="2011-10-16 23:59:59" # To filter by time period: journalctl /usr/bin/dbus-daemon # filters by executable name journalctl _PID=123 # filters by pid journalctl _COMM=sshd # filters by command journalctl _UID=1000 # filters by specific user id journalctl -k # filters only kernal messages journalctl -k --grep="IN=.*OUT=.*" # view packets that were logged by iptables since the machine was last booted
2.2. Info about journals
journalctl -F _SYSTEMD_UNIT # list systemd units logged journalctl --list-boots # list all available boots journalctl --disk-usage # disk usage of all journal files
3. systemd-analyze
boot up inspection
systemd-analyze time # (default) systemd-analyze plot > plot.svg # startup time plot systemd-analyze blame # list running units ordered by time to init
4. systemd-resolved
4.1. Flush DNS cache
pkill -USR1 systemd-resolve # dump all cache into system log if needed journalctl -u systemd-resolved > ~/resolved.txt # dump all logs + cache info into a file if needed systemd-resolve --flush-caches # flush cache
4.2. Common operations
systemd-resolve --status
5. Other systemd tools
systemd-cgls: Show cgroup treesystemd-cgtop: Show cgroup resource usagehostnamectl: play w system hostnamelocalectl: system locale and keyboard layoutcoredumpctl: TODOsystemd-delta: find overidden files