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i broke my bootloader at 1am and fixed it from a live usb, here is the exact rescue

Lena Hoffmann@arch_btw_lena

July 26, 2026 · 2 min read

#1 in Year of the Linux Desktop

Contents(6)

classic arch evening. a kernel update, a reboot, and then just the firmware screen, no grub, no system. my fault, i had been messing with the EFI partition. here is the exact recovery because i always forget the steps and then relearn them in a panic, so now it is written down. distro: arch, systemd, grub, encrypted root. hardware: thinkpad, UEFI.

step 1: boot a live usb

any arch live usb. boot it, get to the shell. do not panic yet, your data is almost certainly fine, the bootloader is just a signpost and you knocked the signpost over.

step 2: find and mount your partitions

use lsblk to see your disks. mount your root partition (for me, unlock the encrypted one first with cryptsetup, then mount the logical volume) to /mnt, and crucially mount your EFI partition to /mnt/boot (or wherever yours lives). this is the step people forget and then wonder why the bootloader fix does nothing: grub lives on the EFI partition and if you did not mount it, you are reinstalling grub into thin air.

step 3: chroot in

arch-chroot /mnt. now you are "inside" your real system using the live usb's kernel. everything you run now affects your actual install.

step 4: reinstall and regenerate grub

  • grub-install pointed at your EFI directory, with the right target for UEFI.
  • grub-mkconfig -o /boot/grub/grub.cfg to regenerate the config so it finds the new kernel.
  • if your root is encrypted, make sure the config and initramfs actually reference the right UUID, this is where i had gone wrong, i had a stale UUID after resizing.

step 5: exit, unmount, reboot, breathe

exit the chroot, unmount everything cleanly, pull the usb, reboot. grub came back. total time maybe 20 minutes, 15 of which was me being scared.

the actual lesson

keep a live usb in your bag, always. and the thing that saved me was not the commands, it was that i knew my disk layout, encrypted LVM on this partition, EFI there, because i set it up by hand and understood it. the person who follows a "just copy these commands" install guide and then hits this has no map. learn your own disk layout before you need it. also, maybe do not reboot into a kernel update at 1am. but we both know i will do it again.

#linux#arch#grub#troubleshooting

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Graham Whitfield@greybeard_graham#2 in Year of the Linux Desktop
arch-chroot and reinstall grub is the modern version of a ritual I have performed on a hundred different systems since the lilo days. The real lesson, as you say, is knowing your own disk layout. I have watched people reinstall an entire OS because they could not face a chroot. Keep the live usb in the bag. Cheers, G.
2 net votes
Prashanth Gowda@prashanth_sre#6 in Year of the Linux Desktop
the "mount the EFI partition to /mnt/boot or the fix does nothing" line is the one that gets everyone. i have done this recovery on a dozen servers and i still forget the efi mount every third time and reinstall grub into nothing. bookmarking so i stop doing that.
3 net votes
Nguyễn Minh Hiếu@homelab_hieu#3 in Year of the Linux Desktop
the stale UUID after a resize is a very sneaky one, i hit the same on a VM and spent an hour because grub looked fine but initramfs could not find root. always check the UUID matches in both places, hope this help the next person :)
3 net votes
Alasdair Reid@onprem_or_die#4 in Year of the Linux Desktop
or run a boot setup that doesnt fall over every kernel update. just saying. but aye, the chroot rescue is a good skill, every one of ye should be able to do it in the dark. decent writeup for once.
5 net votes