Chroot Rescue Guide

Chroot = enter your broken system from the outside and operate on it directly. The Recovery Environment automates common cases; here’s the manual craft.

1. Boot the live ISO, identify partitions

lsblk -f
# typical UEFI layout: p1 = EFI (vfat), p2 = root

2. Mount everything in place

sudo mount /dev/nvme0n1p2 /mnt
sudo mount /dev/nvme0n1p1 /mnt/boot/efi     # UEFI only
for d in dev proc sys run; do sudo mount --rbind /$d /mnt/$d; done
sudo cp -L /etc/resolv.conf /mnt/etc/       # DNS for network inside

Btrfs subvolume roots: mount with -o subvol=@ first (Btrfs Management).

3. Enter

sudo arch-chroot /mnt        # ships on the ISO (arch-install-scripts)

You now have your system’s shell, packages, and configs.

4. Fix things

pacman -Syu                        # finish interrupted upgrades
pacman -S linux mkinitcpio         # reinstall kernel + regenerate images
grub-mkconfig -o /boot/grub/grub.cfg
passwd youruser                    # password resets
nano /etc/fstab                    # UUID corrections
journalctl -b -1 -p err            # inspect the failed boot

5. Leave cleanly

exit
sudo umount -R /mnt
reboot

Gotchas

Encrypted root: cryptsetup open /dev/nvme0n1p2 cryproot before mounting /dev/mapper/cryproot.
Wrong-mode GRUB (installing BIOS GRUB on UEFI box) — match targets: --target=x86_64-efi.
If pacman complains about locks post-crash: rm /var/lib/pacman/db.lck inside chroot.