about systemd

1. systemd = init + inetd
2019-02-13
written by t0spring

2. idx
• what is init
• what is inetd
• combine init and inetd to systemd
• control init thing
• control inetd thing

3. init
• kernel then
• internal service
• such as time service
• ntpd
• chronyd
• with level
• 3 : multi-user
• 5 : graphical(GUI)
• at /etc/inittab, /etc/init.d, /etc/rc.d

4. inetd
• service control
• outer service
• such as httpd
• later
• xinetd
• at /etc/inetd.conf

5. systemd
• combine init and inetd to system
• system = init + inetd
• and parallel
• at /etc/system, /lib/systemd/system

6. control init thing
• systemctl get-default
• systemctl set-default multi-user.target
• systemctl set-default graphical.target

7. control inetd thing
• systemctl status httpd.service
• systemctl stop httpd
• systemctl start httpd
• systemctl is-enabled httpd
• systemctl is-active httpd

8. lab
• boot with your some
• then do it

9. fine