GRUB uses a description (1)

Starting from RedHatLinux7.2, GRUB (GRandUnifiedBootloader) instead of the LILO has become the default boot loader.

Believe that LILO for everyone who is very familiar. This time instead of using GRUB RedHatLinux LILO, GRUB is visible excels. However, relative to the LILO, GRUB or to us to some stranger. This article on the basic situation of GRUB, terminology, interface, commands and configuration file for a presentation, and I hope to everyone to help. First, an overview of GRUB on RedHatlinux mount a system before, it must be a bootloader (bootloader, start the Administrator program) in the specific directives tell it to boot the system. This program is usually located in the system's primary hard disk drive or other know how to start the Linux kernel's media drive. If an x 86 system only RedHatLinux and only one version of the linux kernel, then through the bootloader starts a specific process on RedHatLinux. RedHatLinux Installer allows users to quickly and easily configure the bootloader resides in the primary hard disk drive's master boot record to boot the operating system. However, in order to be more of the Linux kernel or boot other operating systems, it is necessary to understand the need for providing Redhatlinux boot options, as well as understanding the boot process and how to change. This article is to discuss the GRUB, it is RedHatLinux uses to load the operating system on x 86 systems the default method. At the same time, this article will detail is used to control the boot process of various commands and configuration options. Grub defines GNUGRUB (GRandUnifiedBootloader) is a bootloader is installed into the master boot record, master boot record is located on a hard disk to start the sector. It allows is located in the master boot record of the directive in a specific area to mount a grub GRUB menu or command environment. This allows the user to start the operating system of choice, in the kernel boot time pass specific instructions to the kernel, or before the kernel boots to determine some system parameters (such as the size of the available RAM). X 86 boot process when an x 86 machine starts, the system BIOS to start detection system parameters, such as memory size, date and time, disk device, and the disk devices for boot order, etc. Typically, the BIOS is configured to check the floppy drive or CD/DVD drive first (or both), and then attempt to boot from the hard drive. If the removable device, did not find the bootable media, the BIOS is typically the first hard drive initially turned to several sectors, find the instructions for loading the operating system. These initial slice-master boot record-start loading a pre selection process of the operating system, an operating system option traders the grub menu, or an implementation-specific options in the GRUB command line interface. Mount GRUB and the operating system's process, including the following: 1, mount basic bootloader, this is usually the first step. Basic bootloader must be located in the master boot sector of a very small space, less than 512 bytes. Therefore, the basic bootloader has done the only thing is to mount the second boot loader. This is largely attributed to the master boot sector is not enough space for other things. 2. Mount the second boot loader, which is usually referred to as the second step. This second bootloader actually leads to more advanced features that allow users to put into a specific operating system. In GRUB, this step is to let users display a menu or enter the command. 3. Mount in a specific partition operating system, such as the linux kernel. Once the GRUB command line from it, or the configuration file, you receive the correct instruction of the operating system starts, it will find the necessary boot files, and then put the machine's control to the operating system.