Error

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CentOS / RHEL 7 : How to reinstall GRUB2 from rescue mode

1. Boot from the RHEL7 installation DVD by altering the boot order in Bios and selecting DVD media as the first booting preference.

2. At the boot screen, Select the Troubleshooting option at the end of the screen.

3. At the next screen, select the option Rescue a Red Hat Enterprise Linux system.

4. On the next screen, press enter to continue. When asked if you would like Rescue to find your installation, choose Continue.

5. Next step is to change your root directory to /mnt/sysimage using the chroot command. This makes your system the root environment.

# chroot /mnt/sysimage

6.mount DVD

mkdir /test

mount /dev/sr0 /test

7.cd /test/packages

yum reinstall kernel-3*

8. grub2-install /dev/sda

grub2-mkconfig -0 /boot/grub2/grub.cfg

exit

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