About how to start an order in Linux

Article Title: About how to start a Linux-based ordering user. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.

As a Linux enthusiast, I am eager to get new knowledge every day and explore all parts of Linux every day. In this process, Linux cannot be started. There is a protection mode in Win98. You can enter the protection mode to Win98 and repair the system. In Linux, there is also a protection mode, which can be used to fix the system.

Linux boot methods are commonly used in single-user mode, common multi-user mode, full-user mode, and XWin mode. In the single-user mode, the system does not completely run in, but some programs run, and remote logon to Linux is not allowed. The ROOT user performs system maintenance by entering a single user, and the ROOT user directly enters the system without password verification. At this time, the ROOT user has full operation permissions on the system, which can repair the system and damage the system at any time. Here, we will describe some management of a single user:

I. method for implementing a single user

Many methods are used to boot Linux systems, such as floppy boot, LILO boot, and GRUB boot. I will describe these methods separately:

1. Floppy boot

When "BOOT:" is displayed after a floppy disk is started, you can set the startup parameters. Enter "Linux single" here and start the system as a single user.

2. LILO Mode

When starting in LILO mode, after the LILO prompt appears, you should quickly enter kernel/boot/vmlinuz-2.4.7-10 single roo =/dev/hda3, here I am using RedHat7.2, the kernel is 2.4.7-10. Generally, the file name is vmlinuz. You can copy or establish a connection to the kernel file when the system is normal. Single is a single-use method. Root =/dev/hda3 is the root of the Linux system. My computer is equipped with Win98, if only Linux is available. It may be/dev/hda1. On the second hard disk, It is/dev/hdb1. Here is how Linux identifies partitions.

3. GRUB Mode

This method is more complicated. When you enter the GRUB startup screen, press "C" to enter the GRUB command line. If you have a password, press "P" and then enter the password before running the GRUB command line.

In the command line enter the following command can be single user, I still take REDHAT7.2 as an example to illustrate the kernel/boot/vmlinuz-2.4.7-10 single root =/dev/hda3initrd/boot/initrd-2.4.7-10.img boot (hd0, 2) The first two sentences indicate the kernel file. The keyword of a single user is still single. The file names may vary depending on the system. The meaning of boot (hd0, 2) is

Boot from the first hard disk's 3rd partitions.

Ii. methods to prevent entry into a single user

Because a single user has full control permissions on the system, if the operation is improper or is accessed by others, the consequences will be unimaginable. How to prevent the entry of a single user has the following considerations.

1. Protect the/etc/inittab file. If you change 3 in id: 3: initdefault to 1, you can directly access the single-user mode at each startup. For the/etc/inittab file, enter as root and set the attribute to another user through chown700/etc/inittab.

2. If the lilo mode is used for boot, you may use Linuxconf or directly modify lilo. conf to set the waiting time for the boot to 0 or the shortest time. In this case, if you enter the single-user mode, you can use a floppy disk for boot.

3. If GRUB is used for boot, the simplest method is to use the GRUB Password to protect the startup options.

4. In order to prevent remote damage and restart the system, in addition to effectively managing the ROOT password and files in the/etc directory, the CMOS password should also be set, in this way, even if the system is changed to a single user mode, the computer cannot be started directly.