grub引导故障（分区信息损坏）

查看grub信息

[root@test2 Desktop]# cat /boot/grub/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#  all kernel and initrd paths are relative to /boot/, eg.
#  root (hd0,0)
#  kernel /vmlinuz-version ro root=/dev/mapper/vg_jason-lv_root
#  initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-431.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/vg_jason-lv_root rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 rd_LVM_LV=vg_jason/lv_root rd_LVM_LV=vg_jason/lv_swap rd_NO_MD crashkernel=128M SYSFONT=latarcyrheb-sun16 rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-431.el6.x86_64.img

下面要写入的就是这些内容：

• root (hd0,0)
• kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/vg_jason-lv_root
• initrd /initramfs-2.6.32-431.el6.x86_64.img

Red Hat Enterprise Linux 3: Reference Guide

• root (,) — Configures the root partition for GRUB, such as (hd0,0), and mounts the partition.
• kernel </path/to/kernel> — Specifies the kernel file to load when booting the operating system. Replace </path/to/kernel> with an absolute path from the partition specified by the root directive. Multiple options can be passed to the kernel when it is loaded.
• initrd </path/to/initrd> — Enables users to specify an initial RAM disk to use when booting. Replace </path/to/initrd> with the absolute path to the initial RAM disk.

通过更改grub.conf名称模拟grub出错

[root@test2 grub]# mv grub.conf grub.conf.bak
[root@test2 grub]# ls -lh | grep grub
-rw-------. 1 root root  819 May 18 04:15 grub.conf.bak
lrwxrwxrwx. 1 root root   11 May 18 04:13 menu.lst -> ./grub.conf
[root@test2 grub]#
[root@test2 grub]# reboot

根据gru.conf来手动写入:

root+kernel

initrd

boot

重启后正常进入桌面登录

将grub.conf.bak更改回grub.conf

[root@test2 grub]# mv grub.conf.bak grub.conf
[root@test2 grub]# ls -lh | grep grub.conf
-rw-------. 1 root root  819 May 18 04:15 grub.conf
lrwxrwxrwx. 1 root root   11 May 18 04:13 menu.lst -> ./grub.conf
[root@test2 grub]#