2015-03-11 yum usage, single-user mode, rescue mode, RunLevel

Summary of Last lesson review:
1. Installing the System
The virtual machine needs to set not less than 1G of memory, otherwise the graphics will not come out;
The resolution is set to 800*600;
The network card is set to bridge mode (if you do not bridge well, it is set to NAT, also support DHCP to obtain IP automatically);
Partition:/boot 200M, swap 2000M (recommended memory is less than 4G, memory twice times, greater than or equal to 4G to 8G),/remaining;
Minimal installation
2. Ifconfig-a View IP

650) this.width=650; "title=" 1 "style=" border-top:0px; border-right:0px; border-bottom:0px; border-left:0px; Display:inline "border=" 0 "alt=" 1 "src=" Http://s3.51cto.com/wyfs02/M02/72/9C/wKiom1XoM6uhg7OjAAAq9grbo4E947.jpg "" 244 "height="/>

Chinese toggle

vi/etc/sysconfig/i18n
Will lang= "en_US. UTF-8 "replaced with lang=" ZH_CN. UTF-8 "
Edit Save Wq, restart the system, all operations with root.

3. DNS-related
DNS configuration file/etc/resolv.conf
Refer to Li Long post: http://www.aminglinux.com/bbs/thread-7474-1-1.html
4. Remote connection
Use putty to connect to official website http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
Course Outline:
1. Yum uses
Init 5 or STARTX allows us to switch to the graph
Yum update automatically upgrades to latest version 6.6

Unlock Rm-f/var/run/yum.pid
2. Single User
Restart linux,3 seconds, press ENTER.
If you have a grub password, you need to press P first, enter the password before you can do the following
Press E, select the second row, and then press E
Add single or number 1 or letter s on the last side
Press ENTER first and then press B
This will successfully enter single user mode, we can change the root password passwd

Init 3 Entry System

3. Rescue mode

Case: Linux does not start/etc/inittab properly; Change root password with GRUB set password

/boot/grub/grub.conf and/etc/passwd File modification errors

[Learning note] Linux rescue mode operation

Http://www.apelearn.com/bbs/forum.php?mod=viewthread&tid=7523&highlight=%BE%C8%D4%AE%C4%A3%CA%BD

4. 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
Then we can use the command init + runlevel number to switch between modes, for example, after we have installed the graphical interface, in command line mode, the input command init 5 can be entered into the graphical interface. In the graphical interface, open the terminal software, input command init 3 can enter the command line mode. Similarly, we input the init 0 can be shutdown, input init 6 can be restarted
5. Linux boot process

Http://www.apelearn.com/bbs/forum.php?mod=viewthread&tid=7527&highlight=%CF%B5%CD%B3%C6%F4%B6%AF

1. Hardware Boot Boot

2.grub Boot boot process

3. Kernel boot process

4.sys Init initialization phase

5. Start complete

2015-03-11 yum usage, single-user mode, rescue mode, RunLevel