It describes how to update grub2 so it does not use the disk UUID but instead uses the disk physical path. When restoring backup of virtual machine, the backup process may create a new disk with a new UUID.
The server may not reboot if the UUID of the new disk is different from the UUID of the old disk. One possible solution is to ensure that /etc/fstab file uses physical paths instead of UUID. Another solution is to update grub configuration so it uses physical device paths e.g /dev/xvda1 instead of UUID of disk