CentOS GRUB负责管理启动Linux

CentOS GRUB负责是CentOS用户必须学习使用的，由于CentOS GRUB还有很多人不会应用所以由我来简述说明下，至于管用否就看人品了.如何修改CentOS GRUB的开机选项? (OS) (Linux) (Ubuntu) (CentOS) 。CentOS Linux的使用者也不会遇到任何的版权问题。CentOS面向那些需要企业级操作系统稳定性的人们，而且并不存在认证和支持方面的开销。

Abstract CentOS GRUB负责管理启动Linux还是Windows,該如何修改GRUB开机选项呢?
Introduction
为什么需要更改CentOS GRUB呢?
1.当Ubuntu更新新的kernel后,GRUB会自动加上新的kernel开机选项,导致开机选项越来越多,想将不必要的开机选项刪除.
2.CentOS GRUB预设开机为Ubuntu,你可以想将预设开机改成Windows.
3.修改预设CentOS GRUB等待时間.
4.预设不显示GRUB menu,直接進入Windows.
假如你有以上需求,就得手动修改GRUB开机选项.
Solution

开啟CentOS GRUB开机选项档sudo gedit /boot/grub/menu.lst

Q1.当Ubuntu更新新的kernel后,CentOS GRUB会自动加上新的kernel开机选项,导致开机选项越来越多,想将不必要的开机选项刪除.
A1.以下为我所要的开机选项,不需要者可自行刪除之## ## End Default Options ##
title Ubuntu, kernel 2.6.20-16-generic
root (hd0,6)
kernel /boot/vmlinuz-2.6.20-16-generic root=UUID=b923ef76-3246-411c-8095-7bca666b13a5 ro quiet splash
initrd /boot/initrd.img-2.6.20-16-generic
quiet
savedefault
title Ubuntu, kernel 2.6.20-16-generic (recovery mode)
root (hd0,6)
kernel /boot/vmlinuz-2.6.20-16-generic root=UUID=b923ef76-3246-411c-8095-7bca666b13a5 ro single
initrd /boot/initrd.img-2.6.20-16-generic

# This entry automatically added by the Debian installer for a non-linux OS
# on /dev/sda1
title Microsoft Windows XP Professional
root (hd0,0)
savedefault
makeactive
chainloader +1

Q2.CentOS GRUB预设开机为Ubuntu,你可以想将预设开机改成Windows.
A2.修改
## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
#
# You can specify 'saved' instead of a number. In this case, the default entry
# is the entry saved with the command 'savedefault'.
# WARNING: If you are using dmraid do not change this entry to 'saved' or your
# array will desync and will not let you boot your system.
default 2
预设default为 0,表示开机用Ubuntu开机,因为在我的电脑Windows为第三個选项,故default为2

Q3.修改预设CentOS GRUB等待时间.
A3.修改
## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout 3
预设为10秒钟,我改成等待3秒钟

Q4.预设不显示CentOS GRUB menu,直接進入Windows.
## hiddenmenu
# Hides the menu by default (press ESC to see the menu)
hiddenmenu
预设会显示GRUB menu,若你不想显示menu,要当按下ESC才显示,请将hiddenmenu前的#拿掉