initramfs - ERROR: device '/dev/mapper/vg0-root' not found, Skipping fsck

Question

Upon booting my Dell XPS 15 9560 running Arch, I am being dropped into an emergency shell because my devices aren't being found

starting version 239

A password is required to access the luks volume:
mount: /new_root: special device /dev/mapper/vg0-root does not exist.
ERROR: device '/dev/mapper/vg0-root' not found, Skipping fsck.
mount: /new_root: special device /dev/mapper/vg0-root does not exist.
You are now being dropped into an emergency shell.
sh: can't access tty; job control turned off
[rootfs ]#

Output of lvm pvs

[rootfs ]# lvm pvs
  WARNING: Not using lvmetad bacause config setting use_lvmetad=0
  WARNING: To avoid corruption, rescan devices to make changes visible (pvscan --cache)
  PV               VG  Fmt  Attr PSize    PFree
  /dev/mapper/luks vg0 lvm2 a--  <237.74g    0

Output of lvm lvs

[rootfs ]# lvm lvs
  WARNING: Not using lvmetad bacause config setting use_lvmetad=0
  WARNING: To avoid corruption, rescan devices to make changes visible (pvscan --cache)
  LV   VG  Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root vg0 -wi------- <221.74g
  swap vg0 -wi-------   16.00g

That output is really confusing because it shows that vg0-root and vg0-swap both exist, but they just don't appear under dev, including after doing a cryptsetup luksOpen /dev/nvme0n1p3 luks

My guess would be that I'm missing a hook with my mkinitcpio.conf, but this is my mkinitcpio.conf

HOOKS=(base udev autodetect modconf block encrypt lvm2 filesystems keyboard fsck)

Which I don't believe is any different from 5 days ago, the last time it booted just fine. I did run a pacman -Syu earlier today, but I'm not sure how I would find out what exactly broke here.

mkinitcpio -p linux works without errors when chrooted into the drive from a arch usb

edit:

added root=/dev/mapper/luks to my GRUB_CMDLINE_LINUX, and now get the error mount: /new_root: unknown filesystem type LVM2_member'

lvm vgchange -ay vg0

mount /dev/mapper/vg0-root /new_root

exit

Allowed me to boot into my system, but this should be happening automatically with the lvm2 hook and upon restarting, I have to do it again.

Answer 1

What I did to fix this

Switched to systemd initramfs by changing all busybox hooks to their systemd equivalents, and changed the grub DEFAULT_CMDLINE_LINUX to reflect the syntax of sd-encrypt and sd-lvm2.

I then reset my lvm.conf

sudo rm /etc/lvm/lvm.conf && sudo pacman -S lvm2

Answer 2

I had a similar issue, the logical volumes were showing as inactive while doing lvscan.

The only change I did before in the /etc/lvm/lvm.conf was to disable use_lvmetad.

To recover from this scenario I have ran:

rm /etc/lvm/lvm.conf && pacman -S lvm2

but I think it is worth trying to re-enable use_lvmetad and regenerate ram disk:

So:

1. make sure the use_lvmetad=1 in /etc/lvm/lvm.conf

2. if you are changing the option to use_lvmetad=1 , regenerate ramdisk:

   mkinitcpio -p linux