How to install CentOS 6.x

How to install CentOS 6.x

CentOS 6. x installation process many people think that it can be installed, there is no need to understand how to install it, but I have suffered this loss (during the interview), so I should write it down, if you encounter this problem, you can have a reference.

First, let's take a look at the directory of the CentOS installation CD:

Let's explain the functions of these directories (files have no function, they are all KEY files, GPL information, and so on)

EFI # files for EFI boot

Images # install image install. img and some pxe startup files

Isolinux # directory of the boot file, including vmlinuz, initrd. img, and isolinux. bin

Packages # common rpm Packages

Repodata # yum index source, there are some instructions

Here we mainly care about the images and isolinux directories. The EFI directory is only used for EFI boot, so there is nothing to go into, and the other two directories are also attached.

1. Contents of the images directory:

Pxeboot directory:

Install. imgfile: The image where the installer is located. system installation depends on the anaconda program in this image.

Vmlinuz compresses the kernel. The first thing after the boot program starts is to start the kernel;

Initrd. img provides some additional drivers and a simulated file system environment for the kernel.

For efi, skip this step.

2. isolinux directory:

There are many files in this directory. We only need to care about the following:

Isolinux. bin # Boot Program (which can be understood as bootloader), which will be started after BIOS power-on self-check.

Isolinux. cfg # boot program configuration file

Vmlinuz # compressed kernel. After isolinux. bin is started, vmlinuz and initrd. img are started.

Initrd. img # provides the driver and basic system environment for the kernel, which is a small file system. One init program is used by the kernel to start anaconda.

Grub. conf # provides the grub sample configuration file. grub is not started during installation, so grub cannot be used.

We have found that the pxeboot and isolinux directories contain vmlinuz and initrd. img. The files in these two directories are exactly the same.

If we discard the duplicates, we only need to consider the following:

① Isolinux. bin

② Isolinux. cfg

③ Vmlinuz

④ Initrd. img

⑤ Install. img

The general installation process is as follows:

After the disc is inserted and started, the computer will first perform self-check (POST). After the self-check is complete, the BIOS will be started. The BIOS will locate the disc and find the BOOTLoader according to the boot sequence. At this time, the BOOTLoader is isolinux. bin, isolinux. bin according to isolinux. cfg provides a menu interface (to start vesamenu. c32) Let the user select the operation and take a look at isolinux. cfg file

Default vesamenu. c32 # provides the menu program function. You can skip this step if you do not need the interactive mode.
# Prompt 1 # whether to enter the interactive mode, 1 is, 0 is not
Timeout 600 # timeout duration
 
Display boot. msg # displays the boot. msg file, which is useless and can be ignored.
Menu background splash.jpg displays a background file. For more information, see splash.jpg.
Menu title Welcome to CentOS 6.5! # Generate a Welcome to CentOS 6.5!
Menu color border 0 # ffffffff #00000000
Menu color sel 7 # ffffffff # ff000000
Menu color title 0 # ffffffff #00000000
Menu color tabmsg 0 # ffffffff #00000000
Menu color unsel 0 # ffffffff #00000000
Menu color hotsel 0 # ff000000 # ffffffff
Menu color hotkey 7 # ffffffff # ff000000
Menu color scrollbar 0 # ffffffff #00000000 these are color settings
 
Label linux # This is the startup label
Menu label ^ Install or upgrade an existing system # Install or upgrade the system
Menu default # default start label
Kernel vmlinuz # Start the kernel
Append initrd = initrd. img # Start initrd
Label vesa
Menu label Install system with ^ basic video driver # Install basic Devices
Kernel vmlinuz # Start the kernel
Append initrd = initrd. img xdriver = vesa nomodeset # Start initrd and install basic device parameters
Label rescue
Menu label ^ Rescue installed system # Rescue mode
Kernel vmlinuz
Append initrd = initrd. img rescue # rescue Mode Enabled
Label local
Menu label Boot from ^ local drive
Localboot 0 xffff
Label memtest86
Menu label ^ Memory test
Kernel memtest
Append-

You can compare the above menu labelline with the following installation diagram to the splash.jpg image:

Installation diagram:

Background Image (splash.jpg ):

We can see that, in fact, isolinux. bin reads the isolinux. cfg file and starts vesamenu. c32, loads the background image, and then provides the option menu. After you select the installation menu, isolinux displays the selected information (here is the first item ):

Label linux # Is the startup label
Menu label ^ Install or upgrade an existing system # Install or upgrade the system
Menu default # default start label
Kernel vmlinuz # Start the kernel
Append initrd = initrd. img # Start initrd

Start the kernel and initrd (initrd can append parameters), and tell the kernel to perform the installation operation. The role of initrd is to virtualize a basic file system, which contains some commands and drivers. The kernel searches for install according to the program in initrd. img, install. img starts the anaconda program and interacts with the user to complete the installation of the Operating System (anaconda can automatically install the system according to the configuration file, and the kickstart file is required ).

Installation of CentOS text tutorial

Installation of CentOS 6 image and text in VMware

Detailed steps for installing and configuring the CentOS Server

Detailed tutorial on installing CentOS 7.0 on a USB flash drive