Learning sysv-rc-conf in ubuntu

Sysv-rc-confsysv-rc-conf is a powerful service management program. the comments of the masses are that sysv-rc-conf is better than chkconfig. Background 1. Ubuntu runtime Linux systems run at a specified runtime level at any time, and different runtime-level programs and services are different...

Sysv-rc-conf
Sysv-rc-conf is a powerful service management program. the comments of the masses are that sysv-rc-conf is better than chkconfig.
 
Background
1. Ubuntu running level
The Linux system runs on a specified running level at any time, and different running-level programs and services are different. the work to be done and the purpose to be achieved are different, the system can switch between these running levels to complete different tasks.
 
Ubuntu system running level:
* 0: Shutdown level
* 1: run scripts in the rc. sysinit and rc1.d directories at the single user level.
* 2: multiple users, but the system does not start NFS or character mode. in some linux systems, level 2 is the default mode and has network functions, such as ubuntu. debian.
* 3: Multi-user, character mode, system startup with network functions, redhat common operation level
* 4: user-defined level
* 5: graphic interface mode, common redhat running level
* 6: restart level
* S: run only the rc. sysinit file.
 
View the current running level and run the following command:
Runlevel
(Runlevel indicates the last running level and the current running level. "N" indicates that the previous running level does not exist .)
 
Switch the running level and run the following command:
Int [0123456Ss]
(That is, the init command is followed by a parameter. this parameter is the code of the running level to be switched to, for example, shutdown with the init 0 command and restart with the init 6 command .)
 
Linux system startup steps:
1. read the MBR information and start the Boot Manager.
In Windows, NTLDR is used as the Boot Manager. if multiple
For a Windows version, you need to select the system you want to enter in NTLDR.
Linux usually uses the powerful and flexible GRUB configuration as the Boot Manager.
2. load the system kernel and start the init process.
The init process is the root process of Linux, and all system processes are its sub-processes.
3. the init process reads information from the/etc/inittab file and enters the preset running level,
Run the scripts in the corresponding folder of the running level in sequence. The script is usually started with the start parameter.
And point to a program in the system.
Generally, the startup script in the/etc/rcS. d/directory is executed first, and then
/Etc/rcN. d/directory. For example, if you set the running level to 3, the corresponding startup
The directory is/etc/rc3.d /.
4. start Xwindow server xorg based on the script in the/etc/rcS. d/folder.
Xwindow is a graphical user interface system in Linux.
5. start the logon manager and wait for the user to log on.
By default, the Windows system uses the Windows system as the logon manager.
After entering the user name and password, you can log on to the system. (You can go to/etc/rc3.d/
A link named s13tpd is found in the folder)
 
Install: sudo apt-get install sysv-rc-conf
Use: sudo sysv-rc-conf
The operation interface is very simple. you can click it with the mouse, or use the keyboard arrow key to locate it, use the space key to select, press Ctrl + N to flip the next page, press Ctrl + P to flip the previous page, and exit with Q.
Extension:
Remove mysql automatic startup.
Sudo update-rc.d-f mysql remove mysql stochastic startup service
Sudo update-rc.d-f apache2 remove services started by apache2
Check the apache and mysql startup scripts in/etc/rc2.d/. they are usually two Arabic numerals followed by an English letter and the script name. If the English letter is S, it will start automatically, and if the English letter is K, the opposite is true. So you only need to find the apache and mysql startup scripts and change S to K.

Author "paggywong"