Talking about Linux

The Linux system was originally evolved from the Minix operating system written by Andrew S.tanenbaum of the University of Helsinki in Finland, a small operating system used mainly for teaching, January 1991, Tanenbaum students Linus Torvalds found that the teacher's operating system can not meet their own needs, began to develop the operating system, September 1991, Linux0.0.1 appeared, Linus put the system on the Internet, computer enthusiasts and developers on the internet and many other supporters began to improve the system.

Linux was originally named Freax, which was free, Freak (singular), X (Unix), and later published on FTP at the University of Helsinki, and was renamed Linux

June 1996, Linux2.0 launched, Linus Torvalds selected a Penguin icon as a logo and mascot for Linux

Linux Logos and mascots

Linux version number is divided into two parts: Kernel (Kernel) version and release (distribution) version

Major releases abroad
1. Red Hat Linux
2. SuSE Linux
3. Turbo Linux
4. Ubuntu
Major domestic release
1. Red Flag Linux
2. Bid for Pu Wah Linux
3. Blue Dot Linux

The main function of the Linux kernel is to be able to interact with the computer hardware, implement the hardware-to-program control and interface operation, dispatch the access to the hardware resources, and provide an advanced execution environment for the user program on the computer and the hardware-to-virtual interface

Compared to the Windows system, Linux is so popular, widely used in the major companies of the server is its high reliability, good portability, and its code is open source, good openness, which gives all kinds of technical personnel to provide great convenience. Its powerful network function, can serve as application server, file server, print server, mail server, news server, etc., in addition to Linux strong database support, support Oracle, Sqlite, Sybase, DB2, MySQL, PostgreSQL and other databases. At the same time, Linux supports a variety of file systems, multi-user functions

As a result, Linux is widely welcomed by enterprises is not surprising.


To understand Linux, it is important to know its file directory structure, for Linux, everything is a file, any command is stored in the system in the form of a file

All Files under Linux

tree structure,/for the highest root directory
Root:root User's personal folder (home directory)
Bin: Holds commands available to most users
Boot: Store startup files and configuration information, which will be used when the system starts
Dev: storage device file,/DEV/HDC for optical drive
ETC: Store the service configuration file
Home: Other users ' home directories
LIB: The library file required to store the program to run
Media: Mount directory for removable devices
MNT: Device Mount Directory
USR: User program storage Directory
var: storing frequently changed data files
TMP: Storing temporary files

Linux has a total of 7 runlevel, respectively corresponding to the 0--6

init [0123456]

0: Turn off the machine

1: Single User

2: Multi-user status No NETWORK service

3: Network Service with multi-user status

4: System not used reserved to user

5: Graphical interface

6: System restart

The common run levels are 3 and 5, and modifying the default runlevel can be done by modifying the id:5:initdefault of the file/etc/inittab: this line of numbers

Want a deeper understanding of Linux be sure to understand its partitioning

First introduce the partition, whether it is Windows system, Linux system, or some other system, the partition of the hard disk is divided into basic partition and extended partition, and the sum of basic partition and extended partition cannot be more than 4. The basic partition can be used immediately and cannot be partitioned, and the extended partition must be partitioned before it is ready for use, which requires two partitions.

So what is the extension partition going to do? It is a logical partition, and there is no limit to the number of logical partitions.

Windows System Partitioning Example

For Windows systems, there are several partitions with several drives, and each partition has an alphabet identifier, their file structure is independent and relatively easy to understand, but for Linux systems, it can be a bit annoying to understand.

For Linux systems, no matter how many partitions, there is only one root directory in the final analysis! Each partition of a Linux system is used to form part of the entire file system, using a process called "loading". Its entire file system contains a complete set of files and directories, and a partition and a directory link, the partition to be loaded will make its storage space in a directory to obtain.

To view Linux specific partitions, use the FDISK-L command to view

If you want to see which partition a directory is available under, DF [directory full path] command

In short, the Linux partition is mounted in the directory, the following examples illustrate

This file is now stored under boot

This directory stores files in the afternoon after the partition is removed

After re-mount the partition is stored in the/boot directory

Talking about Linux