Linux system Recovery "one"

Lab Environment: RHEL7.0

Experimental content:

1. MBR first 446 bytes corrupted

2. Grub boot file is missing

3. Forget the power-on password

   
   

1.MBR First 446 bytes damaged

1.1 Damage to MBR

[Email protected] ~]# df-h

/DEV/SDA1 497M 119M 379M 24%/boot

[[email protected] ~]# dd if=/dev/zero OF=/DEV/SDA bs=400 count=1

[email protected] ~]# reboot

1.2 Phenomena

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1.3 Fix

1.3.1 Mount CD, CD Boot

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1.3.2 Select troubleshooting, continue to select repair Redhat system

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1.3.3 Important carriage return Knock 3 and then go into the black box interface ready to repair MBR

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1.3.4 Switch root file system, repair MBR

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1.4 Repair Complete, adjust boot order to hard drive boot, restart view

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Repair complete.

2.GRUB boot file is missing

Grub Boot file is/boot/grub2/grub.cfg  

[Email protected] ~]# file/boot/grub2/grub.cfg

/boot/grub2/grub.cfg:ascii text

2.1 Corrupted files

[Email protected] ~]# rm-rf/boot/grub2/grub.cfg

2.2 Phenomena

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2.3 Fix

2.3.1 like repairing MBR, mount the disc, CD-ROM, and enter rescue mode.

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2.3.2 Re-start view

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3 Boot password forgotten.

I've written about how to change the root password by forgetting the boot password. See links for details.

Linux forgot root password solution

This article from the "Technology life, Simple not simple" blog, please be sure to keep this source http://willis.blog.51cto.com/11907152/1855173

Linux system Recovery "one"