CentOS 7: failed to open \efi\centos\grubx64.efi

Wed, 26 Sep 2018 12:52:55 +0000

For some reason one of my CentOS 7 boxes decided to nuke itself yesterday, when I powered it on it prompted me with the following error: “failed to open \efi\centos\grubx64.efi”.
What I did to fix it is:

Boot up a rescue USB, mount the required partitions and chroot.
Add a DNS server:


$ echo "nameserver *.*.*.*" >> /etc/resolv.conf

Enable networking using ifconfig (in my case it was already enabled).
Install some additional grub2 modules:


$ yum install grub2-efi-modules

Reinstall grub, read “/etc/fstab” or “lsblk” command to find it:


$ /sbin/grub2-install /dev/boot/partition

Reinstall grub:


$ yum reinstall grub-efi shim

Rebuild grub.cfg file:


$ grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg

EFI on nagg.eu

CentOS 7: failed to open \efi\centos\grubx64.efi