System START process chroot Ldd,linux run level

The loading process of the system

POST-to-BIOS (BOOT sequence) -- MBR(bootloader,446)--kernel (Load the kernel into memory and unzip, use the virtual root system to load the hard drive (when the pseudo file system exits, the/dev,/sys,/proc directory needs to be transported to the new root ))--INITRD (RHLE5)/ Initramfs (RHEL6)--Theinit process (the main program for user space)

Post-->bios (boot squence)-->mbr (bootloader)-->kernl-->initrd--(ROOTFS)/sbin/init

Virtual root system:

is generally the memory of a space as a disk use (RHLE5 called ramdisk--> name called Initrd,rhle6 called Rmfs

-Name called Initramfs)

Bootloader loading the kernel while also loading the INITRD

Kernel Features:

File Management

Process Management

Memory management

Network management

Security features

Driver Program

Kernel design style:

Single Core : All functions are made into the kernel, i.e. single core. Kernel mode used by Linux. Linux on-line called LWP. (lightweight process)

Modular Design:

Core : KO (Kernel object), Readhat SuSE can implement dynamic load module function kernel naming: vmlinuz-2.6.32-->/Boo t/vmlinuz-* (single core)

/lib/modules/2.6.32* (includes peripheral modules and other content)

Peripheral Modules: kernel path:/lib/modules/"kernel version number named directory" under

Micro-Kernel : Just the core, peripheral functions are made into subsystems, when needed, by the kernel height use, Windows,solaris

Micro cores really support multi-threaded

/lib/modules/2.6.32-279.e16. X86_64/kernel Directory module:

Arch: Platform

Crypto: Encryption

Drivers: Drive

FS: File System

Kernel: Additional features of the kernel itself

LIB: library

MM: Memory Management

NET: Network

Sound: Audio card

chroot command: Switch root to a specified directory

Chroot/path/to/temprootdir [command ...] The default is to run bash

1. Create the specified directory

2. Copy bash to the/bin directory under the specified directory

3. Use the LDD command to view bash's dependent libraries and copy them to the/lib directory

4, Chroot/path/to/tmeprootdir

LDD command

Ldd/path/to/binary_file: Shows the shared libraries on which the binaries depend

[Email protected] kernel]# Ldd/bin/bash linux-vdso.so.1 = (0x00007fff3a1fe000) (virtual, do not need to copy) libtinfo.so. 5 =/lib64/libtinfo.so.5 (0x00007f15df7df000) libdl.so.2 =/lib64/libdl.so.2 (0x00007f15df5db000) Li bc.so.6 =/lib64/libc.so.6 (0x00007f15df219000)/lib64/ld-linux-x86-64.so.2 (0x00007f15dfa1d000)

Operating level: 0-6

0:halt

1:single user mode (single user, direct login to admin, no password required)

2:multi User mode (multi-user, does not start NFS function)

3:multi User mode (multi-user modes, text format, text mode)

4:reseved (Reserved level)

5:multi user mode, graphic mode (multi-user mode, graphical interface)

6:reboot

/etc/inittab: Defines the default level for system startup

Detailed start-up process

System START process chroot Ldd,linux run level