2015.3.11 Second Course

#yum List # #查看yum的软件列表, similar to viewing what software can be installed in the App Store

#cat/etc/issue # #查看系统版本

#yum Update # #升级所有包, change the software settings and system settings, upgrade the system version kernel

#yum Upgrade # #升级所有包, does not change the software settings and system settings, the system version upgrade, the kernel does not change

#uname-A # #可以查看系统位数, x86_64 is a 64-bit system, i386 is a 32-bit system

Rescue mode:

Need to have the installation CD or USB flash drive, reboot into the BIOS to tune into the CD-ROM boot, select "Rescue installed System", the language and keyboard type selection default, Rescue method also remains the default.

Whether to enable the network when using rescue mode, according to the actual situation (if you need to enter the rescue mode remote copy data, you need to enable the network)

Three modes can choose: Shell mode will go directly to the command line, can be done to edit files, modify user password, etc. fakd is the diagnostic mode; reboot will restart directly. Select the first shell mode and execute the command: Chroot/mnt/sysimage.

Operating level:

Linux has 7 operating levels: 0-6

0: Turn off the machine

1: Single User

2: Level 3 without NFS service

3: Command-line mode, that is, no graphics service

4: Reserved

5: Graphical mode

6: Restart

Linux boot process

BIOS power-on self-test, look for the boot media to find the MBR;

After the MBR is found, the location of the kernel is located according to the bootloader (grub) settings;

Execute Linux kernel image code, detect and load hardware driver;

After the driver loading is complete, the kernel gives the initiative to INIT;

Init initializes the system based on the operating level set by the system.

This article is from the "Rhythm" blog, make sure to keep this source http://rhythm.blog.51cto.com/2800158/1619779

2015.3.11 Second Course