Power on and off

Power on is not just a power button to turn off the power off, just turn off the power button? What university is there to ask? That's right, but since Linux is a multi-tasking operating system, you can't guarantee that no one is online when you shut down. If you shut down a large group of people who work online, it will be online at the time. The person who works at the moment is disconnected! That is not a dead person! Some information can be invaluable! In addition, unlike the DOS environment, when Linux is executed, although you will only see a black pressure on the screen, there is no picture at all, but in fact, he has a lot of programs executed under the background, such as mail program. , browser host program, etc., if you shut down casually, it is very easy to damage the hard disk and data transmission! So shutting down under Linux is a university question! Boot (login) Yes! In the absence of power, just press the power button to turn it on! The computer will first read the settings in the BIOS and then start the boot process. Please remember that if your BIOS boot settings are based on CD-ROM, please take out the bootable CD. And it is best not to put a floppy disk in the A slot! OK! Do you remember the boot program installed when you installed Linux? That's right, you can set up the multi-boot Lilo software, and since Lilo's boot information is usually stored in the MBR, the system will first find our Linux settings, so during the boot process, the bottom line of the screen will be Appears: LILO boot:_ This line of words, if you do not act for about ten seconds, the system will boot with Linux default (usually defaulted to Linux boot). If you click the "Tab" button at this time, it should appear on the screen: LILO boot: <== Click here Tab linux dos boot: _ <== The cursor is here, this screen tells you the system At present, there are two magnetic areas that can be booted. The names are linux and dos. In fact, this is the boot name we set during installation! The cursor will be behind boot: At this time, if you press 『Enter』, the system will boot directly with the default linux system. If you hit linux, it will also boot with linux. Of course, dos will start the program with dos! So when you hit dos, you will see the boot screen of windows98! Therefore, if you have not installed Windows 98 before installing Linux, you can use Windows to set your other requirements with dos.

Which, if you boot from Linux, then the system first Will search for your hardware device first, then there will be a lot of hardware information on the screen, you can watch it line by line, or you don't have to look at it, because every time you turn on the information will exist /var/log/dmesg In this file, you can analyze these files carefully after booting up! After searching for software and hardware information, start to start some services (such as: ftp, telnet, talk, etc.! Of course, your other station settings will also be activated. Under the default conditions, the Linux site service will automatically set up two basic small stations for you, one is the mail server, the software is sendmail, and the other is the WWW server, which uses httpd. A set of software, but the initial settings of these services may not be right, this does not matter, because this part of the station will be mentioned later, here is just to tell you in general that Linux will have the default service! After booting up, you need to log in. The login screen looks a bit like this: It will display the Linux kernel version (Kernel) and Red Hat version you are using! Note here that in the above example, because I am using another machine that has been updated with the core as a demonstration, the core version is 2.2.18. If you install it on a CD made from the file on this station, Your core should be 2.2.12-20! Ok, now in the login: place: root, press Enter and then enter your password, you can successfully log in to your machine, root is the system administrator. In addition, it should be noted that due to the confidentiality of this Linux system, the remote is not allowed to log in as root! That is to say, if you connect to this machine in the telnet network in the future, the root account cannot be accessed! So as a system administrator, you'd better have another general account. If I log in to my system as vbird, it looks like the following screen: The system will tell you the time and connection you used to enter the system last time. machine! Then you will be shown your identity and the directory you are in! Note that if you enter as root, it will become [root@tsai root]#. In addition, if you set the boot to X-Window when you installed the settings in the previous chapter, the login screen that appears is a graphical interface. The login fa is the same, but the screen becomes a graphical interface.

Login to Linux host with Windows software. This is one of my favorite features of Linux. After you have set up your Linux host and you have connected to the Internet, you should already have one. The IP of the fa (physical IP), if you have already set up the DNS, it is even better, so you can log in to your host directly using the telnet or netterm connection software! Assuming your DNS is sun.os.test.com, type "Start" -> "Execute" and type: telnet sun.os.test.com, so you can connect to your host anywhere! Great! Shutdown There are many ways to shut down, but one thing to note is that you should not turn off the power directly when you turn it on, or you will not find me when the machine is damaged..... Usually the command to shut down is (# is the prompt character before the instruction!): # shutdown -h now or: # reboot This is the meaning of immediately shutting down and rebooting, but many articles are recommended Before shutting down the program, first write the data stored in the buffer in Linux to the hard disk, so you can execute: # sync This command will write the data back to the disk! Of course, you can also let the system shut down at a fixed time or after a certain amount of time, the command is as follows: # shutdown -h 20:25 <====== The system shuts down at 20:25 today # shutdown -h +10 <======The system shuts down after 10 minutes. During the shutdown process, it also displays a lot of messages to tell you what the system is shutting down. Usually I use the reboot command to restart Linux, and after Linux runs the shutdown program I turn off the power! Because my system is still very simple, does not open a lot of services, naturally do not care too much about the data in the buffer, but the development of good habits is very important, so the correct shutdown program should be developed! You can turn off the program as follows

and then turn off the power after a click on the system! Then if you log in as X-Window, you can press the mouse on the bottom of the screen with a "foot" shape on the bottom left corner of the screen. A string like Windows "Start" will appear. Word, there is a logout option at the bottom. After pressing this option, a box will appear in the center of the screen. There are three options in it. Then select reboot option to reboot! Setting up Lilo's multiple booting, this part should be mentioned later, because there is no such thing as "vi" in the paper processing program (somewhat like PE2 or Hanshu in early DOS), but Because multiple boot and switch are related, so the brothers will write it together, Anyway, here is still assuming that you already know how to use the software processing software under Linux, if you still don't know vi, please turn to Let's talk about the following chapters using vi! To set multiple boot, you only need to modify one file and execute a file! The modified file is in the " /etc " directory and the file name is lilo.conf , so all you have to do is modify the file with vi! Note, because the file to be modified under the admin only has permission to change, so unless you are logged in as root on the host, you must use su to change your identity to become an administrator. The program to be executed is as follows: After logging in as root, go to the etc directory and execute vi, so type: # cd /etc # vi lilo.conf After pressing enter, the screen will look like this: The bottom line of the screen will Tell you the attributes of this file: this file has 20 lines, and a total of 306 characters! You can use the arrow keys to move the cursor. In this file, since I updated the system core first, but I don't want to give up comparing the core of the previous version, I designed two cores to coexist, and also included a Windows boot volume setting.