Linux system Recovery "II"

Lab Environment: RHEL7.0

Experimental content:

1. Startup file corruption

2. Kernel missing

3. Start Run Level Error

4. File causes system not to boot

1. startup file corruption

Linux startup file is/boot/initramfs-3.10.0-123.el7.x86_64.img

1.1 Corrupt Boot file

[Email protected] ~]# rm-rf/boot/initramfs-3.10.0-123.el7.x86_64.img

1.2 Phenomena

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1.3 Fix

1.3.1 mount disc, 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 return hit 3 and then go into the black box interface ready to repair startup files

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1.3.4 Switch root file system, repair startup file

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1.3.5 re-start, the system has been repaired and completed

2. Kernel loss

kernel file is/boot/vmlinuz-3.10.0-123.el7.x86_64

2.1 Corrupt kernel files

[Email protected] ~]# rm-rf/boot/vmlinuz-3.10.0-123.el7.x86_64

2.2 Phenomena

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2.3 Repairing kernel files

2.3.1 like repair startup files, mount the CD, CD-ROM, enter rescue mode, install the kernel.

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2.3.2 Repair complete, re-start

3. Start a Run level error

3.1 Set level 6 for Start level reboot

[Email protected] ~]# Rm-rf/etc/systemd/system/default.target

[Email protected] ~]# ln-s/usr/lib/systemd/system/reboot.target/etc/systemd/system/default.target

3.2 Phenomena

The system is up and running.

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3.3 Fix

3.3.1 like repair startup file, Mount CD, CD boot, enter rescue mode, repair

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3.3.2 Re-start, repair complete

4. File system causes no boot

The file system file is/etc/fstab, and when the file is written incorrectly, the system does not mount the file system correctly, which will cause the system not to start properly

4.1 Destroying file System files

[Email protected] ~]# Vim/etc/fastab

/DEV/MAPPER/RHEL-ROOT/XFS Defaults 1 1

Uuid=91a2d7b9-ce2c-4370-8180-025a6c289c53/boot XFS Defaults 1 2

/dev/mapper/rhel-swap swap swap defaults 0 0

/MNT/HELLO/MNT # # #随便添加错误的文件内容

4.2 Startup phenomenon

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4.3 Directly Enter the password login, modify the correct/etc/fstab file

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4.4 Restart, normal start

This article from the "Technology life, Simple not simple" blog, please be sure to keep this source http://willis.blog.51cto.com/11907152/1855196

Linux system Recovery "II"