Linux Learning _ Rookie Tutorial _1

Linux system Boot process: kernel boot, run init, system initialization, terminal Setup, user Login system

kernel boot : The computer starts up and then the BIOS posts, starting with the boot device (usually the hard disk) set up in the BIOS.

After the operating system takes over the hardware, it first reads the kernel file in/boot.

Run init: The init process is the starting point for all processes in the system. Equivalent to a service in Windows. One of the major tasks of the Init process is to run the boot startup program. And it is based on different occasions to start different programs. This is called "RunLevel". Linux has 7 runlevel.

System initialization: primary completion activates swap partitions, checks disks, loads hardware modules, and other tasks that require priority.

Set up Terminal: The system initialization statement is invoked when Init is run, and when the statement is executed, it returns to Init.init and then opens 6 terminals for the user to log in.

User Login System: (1) command line login (2) SSH login (3) GUI login

How to switch between graphic mode and text mode:

Linux presets provide six command window terminals to let us log in. They are tty1~6; use CTRL+ALT+F1~F6 to switch.

In a VMware virtual machine, use ALT+SPACE+F1~F6 to switch. If you are in the graphical interface, use ALT+SHIFT+CTRL+F1~F6 to switch to the command window.

Linux shutdown

the correct shutdown process sync >shutdown>reboot>halt

Shutdown instruction: Shutdown, man shutdown view Help documentation

If you need to switch to the root user, use sudo su.

Sync synchronizes data to the hard drive

Shutdown-h ' This sever would shutdown after minutes '//Tell everyone that computer 10min is turned off and displayed in the current screen of the logged on user

Shutdown-h now instantly shuts down =halt+poweroff=init 0

Shutdown-h 20:25 The system will shut down at 20:25 today.

Shutdown-h +10 10 minutes after shutdown

Shutdown-r now immediately restarts =reboot =init 6

Halt shutdown system, equivalent to Shutdown-h now and Poweroff

Finally, to summarize: whether it is rebooting or shutting down the system, first run the sync command to write the data in memory to disk.

Well, this morning's Linux study is complete. The main learning of the Linux start-up process, and commonly used switch machine instructions. Individual places do not drill down (such as running the Init run of the statement, how to switch the level of operation), just a quick introduction to the general impression, as to the details of the horse, will certainly know later ~ ~:)

Linux Learning _ Rookie Tutorial _1