[[linux_og_unix:sysadm|Tilbage til Sysadm]]

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==== Systemd vs. SysV init ====

  * [[http://www.linux.com/learn/tutorials/788613-understanding-and-using-systemd/|Understanding and using Systemd]]
  * [[http://0pointer.de/blog/projects/systemd.html|Rethinking PID 1]]
  * [[http://www.bt0.ninja/ten-things-i-love-about-systemd/|10 things I love about systemd]]
  * [[https://niels.kobschaetzki.net/post/2015-11-11-creating-systemd-timers-instead-of-a-personal-crontab/|systemd.timers instead of a personal crontab]]

===== Service Related Commands =====

^  Comments  ^  SysV  ^  Systemd  ^
| Start en service   | service <navn> start   | systemctl start <navn>.service   |
| Stop en service    | service <navn> stop    | systemctl stop <navn>.service    |
| Restarte en service | service <navn> restart | systemctl restart <navn>.service |
| Reload en service | service <navn> reload | systemctl reload <navn>.service |
| Service status | service <navn> status | systemctl status <navn>.service |
| Enable service at startup | chkconfig <navn> on | systemctl enable <navn>.service |
| Disable service at startup | chkconfig <navn> off | systemctl disable <navn>.service |
| Check om en service er enable at startup | chkconfig <navn> | systemctl is-enabled <navn>.service |

===== Runlevels =====

^  Comments  ^  SysV  ^  Systemd  ^
| System halt |  0  | runlevel0.target, poweroff.target |
| Single user mode |  1,s,single  | runlevel1.target, rescue.target |
| Multi user |  2  | runlevel2.target, multi-user.target |
| Multi user med netværk |  3  | runlevel3.target, multi-user.target |
| Eksperimental |  4  | runlevel4.target, multi-user.target |
| Multi user med netværk og grafisk mode |  5  | runlevel5.target, graphical.target |
| Reboot |  6  | runlevel6.target, reboot.target |
| Emergency shell |  emergency  | emergency.target |
| Skift til multi user runlevel %%/%% target |  init 3  | systemctl isolate multi-user.target |
| Check current runlevel |  runlevel  | systemctl get-default |
| Change default runlevel |  Ret i %%/etc/inittab%%  | systemctl set-default multi-user.target |

===== Diverse =====

^  Comments  ^  SysV  ^  Systemd  ^
| System halt | halt | systemctl halt |
| Power off | poweroff | systemctl poweroff |
| Restart | reboot | systemctl reboot |
| Suspend | pm-suspend | systemctl suspend |
| Hilbernate | pm-hilbernate | systemctl hibernate |
| Follow system log file | tail -f /var/log/messages, tail -f /var/log/syslog | journalctl -f |

===== Systemd kommandoer =====

^  Comments  ^  Systemd  ^
| Kill processes related to a service | systemd kill <navn> |
| Get logs or events for today | journalctl --since=today |
| Check boot time | systemd-analyze <time> |
| Hostname m.m. | hostnamectl |
| Tid, dato, tidszone m.m. | timedatectl |

{{:linux_og_unix:systemd-info.png?direct|}}