Get a thorough understanding of Linux system failures and solve

Thorough understanding of Linux system failures and resolution 2009-12-25 10:24 anonymous NET130font Size:T | T

Often when the application of Windows operating system, we will be a lot of system failure, so many people began to apply the Linux operating system, but the Linux operating system also has some system failures, the following is the Linux system fault diagnosis explained. I hope you can understand these Linux system failures.

AD:2014WOT Global Software Technology Summit Beijing Station course video release

Often when the application of Windows operating system, we will be a lot of system failure, so many people began to apply the Linux operating system, but the Linux operating system also has some system failures, the following is the Linux system fault diagnosis explained. I hope you can understand these Linux system failures.

Linux System fault Diagnosis

1. Startup failure

This is a common problem encountered in Linux operating systems. The main reasons why the system does not start are: During the installation of the Linux operating system, the Lilo configuration information is wrong, which causes the system not to start properly after installation, and the reinstallation of other operating systems often results in the original Linux not booting. Because these newly installed operating systems default to no other operating system on the computer, overwriting the master boot record (MBR) of the hard disk, overwriting the LILO system boot program in the Linux operating system, resulting in the inability to start Lilo at the end, and during operation of the Linux operating system, An exception occurred because of a running bad Linux command that caused the system to restart.

Workaround:
If the Linux operating system during the installation process or after the installation process, the creation of a Linux system Emergency Boot Disk group, the use of these emergency disk boot system can enter the system, and then the corresponding error, configuration can solve the problem; Here are three ways to solve the problem:
(1) Enter Linux operating system single user mode, after the boot prompt, type: Linux A, this mode starts the Linux,lilo configuration and the network configuration information is not loaded during the startup process.
(2) CD-ROM boot, with the first Linux operating system installed on the CD (boot CD-ROM) to boot the hard disk Linux system, the motherboard BIOS to set up the CD-ROM boot, restart the machine, the boot: prompt type:
Vmlinuz root=/dev/linuxrootpartition NOINITRD
Where root= is followed by the partition number of your Linux root partition, which is the partition location of the hard disk where the root file system of the Linux system resides, for example: Vmlinuz Root=/dev/hda3 noinitrd. Enter the Linux system after entering. If you want to restore the compromised Lilo system boot program, you can edit/etc/lilo.conf and then run/sbin/lilo. This approach is also suitable for other causes of Linux operating system damage. (Note: The floppy disk starts the operating system as in the same process).
(3) Run the Loadlin program boot system under DOS. When using a Linux system on a personal computer, Linux is usually co-existing with Windows 9x or Windows 2000. If you know the exact installation partition of the Linux system on the hard disk and have the Loadlin program (which is available under the Dosutil directory on the Red Hat Linux CD), you can also start the Linux system. Loadlin is a DOS system program, running it can start the Linux system directly from the DOS system, quickly into the Linux environment. In addition to the Loadlin program, a Linux boot kernel image file Vmlinuz is required, which is available under the images directory of the Red Hat Linux CD. For example, if you enter the DOS command mode under the Windows 2000 system, and then run the following Loadlin command, you can re-enter the Linux system:
Loadlin Vmlinuz root=/dev/linuxrootpartition
Once the command has been executed, boot the Linux system. After you log in as root, after editing/etc/lilo.conf, run/sbin/lilo, and then reload the LILO system boot into the MBR.

2. File system failure

In the Linux operating system, this is also a frequently encountered failure. The file system is corrupted due to an abnormal shutdown of the system, or sudden power-down.

Workaround:
When the file system is compromised, the file system can be repaired using the appropriate FSCK command. For example, the following command:
Fsck/dev/hda5
Refer to the man reference manual for instructions on how to use the specific parameters of the fsck command. If you are using a file system of type EXT2FS, you can run the E2FSCK command from a floppy disk to correct corrupted data in the file system.
But one thing to note: If the file system is damaged because the super block is corrupted, the Super block is the "head" of the file system. It contains information such as the state, size, and free disk blocks of the file system. If a file system's Super block is damaged (such as accidentally writing data directly to the file system's Super block partition), then Linux may not recognize the file system at all, even with fsck or the e2fsck command. At this time, only to the installation CD to see if there is a corresponding file system, this file overwrite the original operating system is corrupted files to recover. If you accidentally delete the important files in the system, you can also use this method to try.

3. function library Failure

In the Linux operating system, if the function library files in the system are inadvertently destroyed, or the symbolic links in the/lib directory are broken, the commands that rely on these libraries will not be executed. This is also a more common system failure.

Workaround:
The simplest solution is to start the system with the first aid startup disk set, install the hard disk file system in the/mnt directory, and then repair the library in the/mnt/lib directory.

4. Login system failure

The system password file was modified because the administrator forgot the password, or because the system was hacked by the hacker. The administrator may be unable to log on to the system with an account.

Workaround:
Method one, when the system starts, enter single-user mode (Linux), and then use the passwd command to reset the password, or modify the password file to return to normal.
Method Two, start the system with the first aid Startup Disk group, and then install the file system of the hard disk into the/mnt directory and edit the/mnt/etc/passwd file for recovery.
Method Three, the installation of the system's hard drive is removed, placed in another Linux system, and then (Mount) Mount the system installation area of the hard disk, the secondary hard disk partition/etc/passwd,/etc/shadow,/etc/group file overwrite or modify, can also be restored.

5. KDE environmental failure

If the KDE environment of the Linux system does not start properly, for example, after running the STARTX command in a normal account, it appears: "... can not start X server. Perhaps don't have the console OWNERSHIIP? "A similar hint. The reason for this is that it is possible that other users have run the KDE environment and left a cache file in the system that identifies the user.

Workaround:
Run the following command:
rm-rf/tmp/*
Then, rerun the STARTX command to enter the KDE environment.

If you run the STARTX command as a normal account, the error message "Can not start X server" appears, and the English characters with the error prompt are constantly tumbling upward, resulting in the inability to enter the KDE environment. This situation may be due to an unhealthy shutdown of the Linux system, resulting in an inability to enter the Linux KDE environment.

Workaround:
Log in as root under Console, type the Setup command, the System Settings menu, select the "X Window Settings", and follow the prompts to correctly set the type of display, refresh rate, memory size, resolution, and so on. This will reset the X window in the system again,

If there is no error, the system will automatically start the KDE environment, it may be important to note that when set up with the Setup command, there may be a large number of English characters tumbling on the screen, it does not matter, please continue to see the screen, using the TAB or the arrow keys for the above configuration, the configuration is correct, Will immediately restore the KDE environment.

Through this article can learn the solution of Linux system failure.

"Editor's recommendation"

1. Virtualization Technology for Linux Xen Beginner's Guide to Virtualization
2. Dealing with Linux kernel security
3. Shell programming shell basic syntax for Linux
4. Linux shell programming methods for running shell programs
5. Linux shell Programming Bash's internal commands

Get a thorough understanding of Linux system failures and solve