Arch Linux

mongoose

Member

Registered: 2015-01-24

Posts: 16

[SOLVED] Do not understand how tocorrectly mount device

Trying to fix broken grub. I followed multiple guides without any succes.

After loading into archlinux iso fdisk -l returns

/dev/sda1 ... EFI System
/dev/sda2 ... Linux filesystem

I mount /dev/sda2 with

mount /dev/sda2 /mnt

then I'm trying to chroot with

arch-chroot /mnt

but got the error

mount: /mnt/proc: mount point does not exists.
             dmesg(1)...
==> ERROR: failed to setup chroot /mnt

I use btrfs if it makes any difference and

ls /mnt

returns

@ @.snapshots @home @log @pkg

so as I understood I actually need to mount @ but I don't know how.

Last edited by mongoose (2023-01-10 19:12:53)

just4arch

Member

Registered: 2023-01-07

Posts: 127

Re: [SOLVED] Do not understand how tocorrectly mount device

You're looking for

man 5 btrfs

specifically "subvol=" or "subvolid="

The full syntax should be in the /etc/fstab you created when installing the system, so mount it as you did there (see /mnt/@/etc/fstab while mounted if you can't remember).
chrooting into /mnt/@ should work, too.

P.S.:
Don't forget to mount the EFI partition, if you want to fix grub.

mongoose

Member

Registered: 2015-01-24

Posts: 16

Re: [SOLVED] Do not understand how tocorrectly mount device

chrooting into /mnt/@ should work, too.

P.S.:
Don't forget to mount the EFI partition, if you want to fix grub.

Thanks.

Seems like just chrooting into /mnt/@ works with some errors.

But I have mounted into it with

mount /dev/sda2 -o subvol=/@ /mnt

But now after mounting /dev/sda1 into /boot/efi and installing grub

grub-install --target=x86_64-efi --efi-directory=<em>/boot/efi --bootloader-id=GRUB

and

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

It only make visible UEFI firmware setting entry, so grub is now working but can't detect my OS.

Relevant part of the /etc/default/grub that I have

GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_backloght=vendor"
GRUB_CMDLINE_LINUX="rootflags=subvol=/@ rootfstype=btrfs"

Any suggestions what to do next?

mongoose

Member

Registered: 2015-01-24

Posts: 16

Re: [SOLVED] Do not understand how tocorrectly mount device

Reinstalling Linux

pacman -S linux

helped. Now it works.

Last edited by mongoose (2023-01-10 17:50:16)