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 boot
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.
CentOS 7 and the kernel is now on
Thanks for any help you can provide.