Arch Linux

JacoNIX97

Member

Registered: 2017-02-14

Posts: 43

UEFI GRUB not showing up in dual boot system after power shortage

I have a dual boot system between Windows 10 and Arch Linux. My disk setup is: separate boot partition, root and home on LVM volumes in a LUKS container, EFI partition. Windows is on another HDD without EFI partition. A couple of days ago the PC suffered a power shortage and now the BIOS directly loads the Windows Boot Manager. Secure boot is disabled (I can boot Arch live USBs). In the BIOS settings I cannot modify the UEFI HDD priorities as the only available entry is Windows. I've tried reinstalling the GRUB from a live but it returns the error:

/usr/lib/grub/x86-64-efi/modinfo.sh doesn't exist

but it does exist. I don't know if it's necessary to reinstall it as the GRUB directori in the EFI partition exists. Before the shortage everything worked as intended. Now Windows loads slower than before the incident. I've run fsck on the filesystems and it detected problems in /boot and /boot/efi but it seems to have solved them. What can I do to solve?

Condor

Member

Registered: 2017-12-01

Posts: 54

Re: UEFI GRUB not showing up in dual boot system after power shortage

Boot into an Arch Live ISO and verify you have booted the UEFI version. Do so with

efivar -l

It should list several variables. If it does not, reboot into the UEFI firmware and make sure to boot the Live ISO marked with “UEFI” (an unmarked version would usually be the BIOS variant).

Then try efibootmgr to recreate the missing boot entry for GRUB. Look for the grubx64.efi file in the EFI partition to derive the correct path (usually EFI\GRUB\grubx64.efi). It will automatically sort the newly created entry as the first boot option.