1. Basic understanding of Linux and basic understanding of linux

1. Basic understanding of Linux and basic understanding of linux

LINUX features:

1. Openness: open source;

2. Multi-user multi-task environment;

3. Good User Interface: provides two interfaces:Character InterfaceAndGraphic Interface(XWindow system );

4. device independence;

5. Rich network functions: built-in TCP/IP

 

There are two Linux kernel versions:Stable versionAndDevelopment version.

The format of the Linux kernel version is as follows:A. bb. cc

 

Swap partition:

UsedVirtual MemoryIn this example, user data cannot be saved.

Boot partition:

Used to saveStart the systemRelated Files. Generally, this partition is set to MB.

Root partition:

Used to placeFile System RootAll documents are stored in this partition, such as the user's home directory and various program directories.

 

Linux root Password Change command:

1. Log On As root.

2. Open the terminal and enter passwd.

3. Enter the First password when "New password:" is displayed.

4. After the password is entered for the first time, "Retype new password:" is displayed. Enter the password again to change the password.

 

Shutdown command Halt:

Halt

Shutdown

Poweroff

Reboot

 

Press the combination keyCtrl + Alt + Fn(Where n is 1 ~ 6) enter the six character terminal interfaces respectively.

 

Init process:

When Linux is started,

Run/Sbin/initProcess,

Then, the init process starts subsequent tasks, such as multi-user environments and networks.

The id (PID) of the init process is 1, and there is a parent process id (PPID) 0.

Note that,The init process is always running.

This process must be used when running/Etc/inittabFile, This isInitProcess configuration file.

 

RHEL supports 7 linux runtime levels. Different runtime levels are defined as follows:

0: Shut down. Shut down the computer.

1: single-user mode, similar to the safe mode in Windows XP.

2: multiple local users without support for remote networks (such as NFS.

3: The full multi-user mode is a standard operation level.

4: Generally, it is not used in some special cases.

5: X11. Enter the graphic interface.

6: restart.