My problem with Arch Linux

Last week, I had a problem with my Arch Linux installation. I have been using Arch for over 4 years, and I must say that it is the most stable distribution that I have used in over 14 years. However, I made a mistake by modifying the Grub config (I hate you Nvidia, I hate you).

I have a somewhat special installation of Arch Linux with a fully encrypted disk over GPT, which caused one of the problems. First of all, after modifying the Grub config, I saved and updated it and then restarted my PC (at least I had saved a backup of my old Grub config). After that, I only had an infinite loop of reboots on my computer.

Normally, you would have a message to decrypt your disk, and then the Grub would be displayed. However, after my changes, after entering my decryption password, Grub just crashed, and my PC started to reboot.

Attempting to decrypt master key…
Enter passphrase for hd1, gpt2.

To repair this issue, you need to reinstall GRUB, and in my case, the following were the necessary steps:

---

Step 1 — Boot a Live CD of Arch Linux

Boot from an Arch Linux ISO. Any recent one will do.

Step 2 — Identify the encrypted partition

Use lsblk to identify the encrypted partition.

lsblk

Step 3 — Unlock the encrypted partition

cryptsetup luksOpen /dev/sda1 cryptdiskb4rt

Step 4 — Scan for LVM volume groups

Use vgscan to detect the LVM volume group from this encrypted partition.

vgscan

Step 5 — Activate the volume group

vgchange -ay

Step 6 — Find your root logical volume

Use lvscan to get the LVM name from your root filesystem. You will get something like this:

ACTIVE '/dev/vg/swap' [8.00 GiB] inherit
ACTIVE '/dev/vg/root' [500.00 GiB] inherit
ACTIVE '/dev/vg/home' [1.32 TiB] inherit

Step 7 — Mount your root volume

mount /dev/vg/root /mnt

Step 8 — Bind mount the virtual filesystems

Don’t forget to mount these — GRUB reinstall needs them:

mount --bind /dev /mnt/dev
mount --bind /sys /mnt/sys
mount --bind /proc /mnt/proc

Step 9 — Chroot into your Arch installation

chroot /mnt /bin/bash

Step 10 — Reinstall GRUB

grub-install /dev/sda

Step 11 — Rollback your configuration

Edit and rollback your configuration from /etc/default/grub to the last known good state. If you saved a backup (you did, right?), now is the time to use it.

Step 12 — Regenerate the GRUB config

grub-mkconfig -o /boot/grub/grub.cfg

Step 13 — Exit and reboot

Exit the chroot and reboot:

exit
reboot

---

After that, finally I’m able to use my PC again.