Linux Rescue mode Restore grub

You will be able to use rescue mode to recover from grub at work. Rescue mode can also be used to restore the root password.

Use dd If=/dev/zero OF=/DEV/SDA count=1 bs=300 to destroy and restart the boot sector

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Boot press F2 into BIOS setup Cd-dvd boot, depending on the machine to enter the BIOS is different. and into rescue mode.

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Choose the language, here can not choose Chinese, will be garbled, other has not chosen

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Select keyboard

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Whether to set up the network, if required optional general select No

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Select continue can also be read-only to mount the selected read-only

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Here tell us/the location of the file

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Select the first entry

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Enter rescue mode input chroot/mnt/sysimage switch to the current root directory and execute the GRUB command. Enter root (hd0,0) If you are prompted for the error root (hd0,1) If there are multiple disk root (hd1,0) such a test. This step is to find the root of the disk there, enter setup (hd0) to load grub into the disk

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Exit GRUB Exit Bash input reboot and restart

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System has been restored

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The second experiment: Deleting a/boot/grub/grub.conf

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Reboot is as follows

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Input root (hd0,0) if not the same as the previous experiment to find, and enter the kernel version number, as well as the location RHGB display progress bar, quiet does not show the details. Restart

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After entering the system, I'm going to rebuild grub here because I just dropped grub.conf.

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Default=0 title from 0 to start the experiment in the wrong, why not error? This has to be checked.

Timeout=5 This, needless to say.

Root (hd0,0) kernel location

The version number of the kernel can be passed.! Ls/boot/v (can be complete) to find. The input parameters of the kernel can be come through. Blkid/dev/sda3 to find (Sda3 is where my original root partition is located, which differs depending on the root partition)

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Pass.! ls/boot/i (full complement) look up

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Save and restart

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An error occurred, check the kernel version number and kernel image file you just entered to find the problem

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By looking, the kernel device is found to have more/boot/dev/sda3 and the file behind the UUID has double quotes. The kernel image file finds that Q is more than/boot and the version number is different from the kernel file. Restart after correct

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System is normal after reboot

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Through these two experiments found that the boot sector damage and configuration file corruption repair is not the same, is not really such a waiter after further discovery

Linux Rescue mode Restore grub