Arch Linux

rbaj

Member

Registered: 2016-01-27

Posts: 36

[SOLVED] Dual boot - grub not booting Arch

I reinstalled arch to add full encryption (not including /boot) with LUKS on LVM on my macbook, dualbooting with macos. I must have messed up reinstalling the bootloader because I had different kernel versions according to $uname -r and $pacman -Q. I sorted that out with some help from the forum, but now I'm trying to fix the bootloader mess I've made. Currently macos boots fine but when I try and boot Arch I just get the grub command line. Can someone sanity check what I'm doing?

Partition map:

/dev/sda1 - ESP
/dev/sda2 - Apple
/dev/sda3 - Apple
/dev/sda4 - Apple
/dev/sda5 - /boot                  
/dev/sda6 - /system (LUKS)
    - /dev/mapper/vg-root        /
    - /dev/mapper/vg-home     /home
    - /dev/mapper/vg-var         /var

1) Boot into live usb and unlock LUKS container
2) Mount the three LVM partitions as above to /mnt
3) Mount boot to /mnt/boot
4) Mount ESP to /mnt/boot
5) #genfstab -L /mnt > /mnt/etc/fstab
6) #arch-chroot /mnt
7) #grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=arch-grub (runs without errors)
8) #grub-mkconfig -o /boot/grub/grub.cfg (warnings related to lvmetad but no errors)
9) exit and reboot

Thanks for your help

EDIT:
It now boots and asks me for the encryption passphrase but then I get

mount: /new_root: unknown filesystem type 'LVM2_member'.
You are now being dropped into an emergency shell.
sh: can't access tty; job control turned off
[rootfs ]#

Is this an fstab problem?

Last edited by rbaj (2017-10-19 14:09:47)

rbaj

Member

Registered: 2016-01-27

Posts: 36

Re: [SOLVED] Dual boot - grub not booting Arch

In my kernel parameters I had

cryptdevice=/dev/sda6:vg-root root=/dev/mapper/vg-root

which needed changing to

cryptdevice=/dev/sda6:vg root=/dev/mapper/vg-root

Don't know how it managed to boot with that before.. anyway fixed now.