Easy way to tell which Init System you are using? And how to manipulate services in different Init System.

Tell the difference of Init Systems

systemd, SysVinit, Upstart, Supervisor

You must have heard these terms and known their job is “start other process”, but given a Linux system, can you tell which Init System it is using? And how to stop or disable service?

init is the first process run on Linux so it has pid=1. init keeps running as long as the system does. All other processes is started by init.

Earlier Linux distributions employed various Init System, but most latest distributions move to systemd.

init platfor controller directory note
systemd Red Hat family, Debian >= 8, Ubuntu >= 15.4 systemctl /etc/systemd/system/, /run/systemd/system/, /run/systemd/generator.late/, /usr/local/lib/systemd/system/, /usr/lib/systemd/system/ compatible with SysVinit by systemd-sysv-generator, doesn’t honor priorities by /etc/rc?.d/
SysVinit earlier Linux service /etc/rc/, /etc/init.d/  
Upstart Ubuntu < 15.4 start, stop, restart, status /etc/init/  

How to manipulate services?

init create remove start stop enable disable
systemd create unit_name.type_extension in /etc/systemd/system/ rm /etc/systemd/system/unit_name.type_extension; systemctl daemon-reload; systemctl reset-failed systemctl start foo systemctl stop foo systemctl enable foo systemctl disable foo
SysVinit create scripts in /etc/init.d, then run update-rc.d or chkconfig mv /etc/init.d/foo.conf /etc/init/foo.conf.disabled service foo start service foo stop update-rc.d foo enable update-rc.d foo disable
Upstart create /etc/init/foo.conf mv /etc/init/foo.conf /etc/init/foo.conf.disabled service foo start service foo stop rm /etc/init/foo.override echo ‘manual’ | sudo tee /etc/init/foo.override

systemctl daemon-reload; systemctl reset-failed

Supervisor looks simple, can it replace other Init System?

Brief answer: NO. Supervisor’s biggest advance is its convenience, but it just covers a subset features which can be done better by like systemd or SystemVinit.


https://unix.stackexchange.com/questions/233468/how-does-systemd-use-etc-init-d-scripts https://www.turnkeylinux.org/blog/debugging-systemd-sysv-init-compat http://linoxide.com/linux-command/systemd-vs-sysvinit-cheatsheet/ http://www.tecmint.com/systemd-replaces-init-in-linux/ http://www.pcworld.com/article/2841873/meet-systemd-the-controversial-project-taking-over-a-linux-distro-near-you.html http://www.tecmint.com/best-linux-init-systems/ https://askubuntu.com/questions/19320/how-to-enable-or-disable-services https://fedoraproject.org/wiki/SysVinit_to_Systemd_Cheatsheet