Shulou(Shulou.com)06/01 Report--

System recovery technology

Recovery method of 1.mbr error

Dd if=/dev/zero of=/dev/vda bs=446 count=1

Reboot

Open the virtual manager at this time

Boot with CD or network card

Select troubleshooting

Select rescue a red hat.

The original root directory will be mounted to / mnt/sysimage

Choose to continue

Enter grub2-install / dev/vda

Then ctrl+d twice.

Force shutdown to change the first boot item to hard disk boot

two。 Delete grub2.cfg

Enter / boot/grub2/

Delete grub2.cfg

Reboot

Enter grub2-mkconfig > / boot/grub2/grub.cfg after successfully opening it.

If there is no ip input / etc/init.d/network restart

Yum install

3. Delete img

Enter / boot to delete initXXXXXXXXXXX.img

Delete vmliXXXXXXXXXXXXX.img

CD-ROM starts rescue mode

Yum install lftp-y

Lftp IP installs Paclages kernel-3.10 in yum source

Exit restart and change the hard disk to the first startup item

4. Modify the password

Forget the root password:

First change selinux to disabled

Press e to edit when booting

Delete the position from 8 to ro

Change it to rw rd.break

Ctrl+x

5. Modify link

Rm-fr / etc/systemd/system/default.target

Ln-s / usr/lib/systemd/system/poweroff.target / etc/systemd/system/default.target

System paralysis

Select kernel and press e to edit

Force to interrupt the system on

Rm-fr / etc/systemd/system/default.target

Ln-s / usr/lib/systemd/system/graphical.target

/ etc/systemd/system/default.target

Graphical.target is to launch the physical graphical interface.

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