Troubleshooting Linux boot failure in rescue mode

A. system does not start properly due to MBR failure (simulates MBR failure using the following command )

DD If=/dev/zero OF=/DEV/SDA bs=446 count=1

2. After the failure, the system will fail to enter the following conditions

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3. Fault appears, now need to put the CD, reboot, CD boot, press F10 save exit

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4. Enter the following command in the Shell to restore

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Second, because the/boot/grub/grub.conf file loss caused the system to fail to boot, the following situation occurs

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1. Recovery mode One, if the original backup, enter the rescue mode after entering the chroot/mnt/sysimage After the backup of the configuration document directly copied back on the line

2. Recovery Method II,

Enter root under grub> (hd0,0)

kernel/vmlinuz-2.6.32-431.el6.i686 ro Root=/dev/sda3 rhgb quiet

Initrd/initramfs-2.6.32-431.el6.i686.img

Boot

Note: where ROOT=/DEV/SDA 3 needs to be tested

Initramfs Each version is different before testing it is best to back up the view

3. If there is an error message file in the configuration file, the boot will appear black screen

Troubleshooting Linux boot failure in rescue mode