I have tried switching my server to a different kernel from what my hosting provider supplies. It should just be a case of updating the kernel from the hosting providers management pages, reboot and the default CentOS kernel is used. This has worked on 1 server but not on the other.

On the broken server it just boots to a grub2 menu. I've managed to get it boot again by running the following:

set gfxpayload=text
insmod gzio
insmod ext2
linux16 /boot/vmlinuz-3.10.0-693.5.2.el7.x86_64 root=/dev/sda ro crashker
nel=auto rhgb console=ttyS0,19200n8 net.ifnames=0
initrd16 /boot/initramfs-3.10.0-693.5.2.el7.x86_64.img

I took these by looking at the /boot/grub2/grub.conf on the server that did work without issue.

After doing the following the server succesfully boots up, but the changes aren't persistent, if I reboot I'm back to the grub2 menu and I need to do it again.

I've looked around and saw some places say to run update-grub but I don't have that command.

I also found to try the following:

grub2-mkconfig -o "$(readlink /etc/grub2.conf)"

This just seems to print the script out and doesn't do anything. If I reboot again I'm back to the grub2 menu.

Anyone got any ideas on how to resolve this.

I'm running CentOS 7 and the kernel is now on 3.10.0-693.5.2.el7.x86_64

Thanks for any help you can provide.

1 Answer 1


I found out I should have run grub2-mkconfig -o /boot/grub/grub.cfg to save the changes instead.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.