Arch Linux

*vitali*

Member

Registered: 2009-12-20

Posts: 83

Cannot Determine Major/Minor for Root partition after kernel upgrade

After kernel upgrade to 3.1.3  (or maybe some other upgrade that came along with it not sure) can no longer boot the system, since it says cannot determine minor/major for the root partition.  How can I fix this (do not want to reinstall).

jongeek

Member

Registered: 2011-12-01

Posts: 1

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

I had the same issue booting tonight after a "pacman -Syu". I tracked it down to a bug of some sort in the init and init_function scripts built by mkinitcpio into the initramfs. The output of "waiting for device <blah>" gets sucked into the $root device variable, so its looking for a root device of "waiting for device /devsda1 ... /dev/sda1" with a newline thrown in there for good measure.

The quick workaround is to add "quiet" to your kernel line in /etc/grub.conf. This prevents the "waiting for" message from being printed. So my grub.conf line that changed was

kernel /boot/vmlinuz-linux root=/dev/disk/by-label/archusb ro

to

kernel /boot/vmlinuz-linux root=/dev/disk/by-label/archusb ro quiet

I haven't figured out exactly how the variable gets corrupted but this allows you to boot.

*vitali*

Member

Registered: 2009-12-20

Posts: 83

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

Yes that seemed to make it work. Unfortunately I have already reinstalled.

Last edited by *vitali* (2011-12-01 02:41:01)

markhadman

Member

Registered: 2010-10-09

Posts: 39

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

Adding 'quiet' to the kernel boot line worked for me too. What a curious bug...

edit: problem still exists after today's linux/mkinitcpio update. I will attempt to file a bug report.

edit: https://bugs.archlinux.org/task/27385

Last edited by markhadman (2011-12-01 14:25:15)

mdev

Member

Registered: 2010-01-29

Posts: 15

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

Thank you! I spent hours fiddling with mkinitcpio until I found this bug report ... there should be a notice on the main page for this.

SkyTod

Member

Registered: 2009-09-01

Posts: 226

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

Same to me and quiet in grub doesn't fix it.
Is there another way?

SkyTod

Member

Registered: 2009-09-01

Posts: 226

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

After

mount -t ext4 /dev/sda1 /

I see

modprobe: FATAL: Could not load /lib/modules/3.1.4-1-ARCH/modules.dep

But I have: /lib/modules/3.1.4-1-ARCH/modules.dep.bin
Can I recover my system without reinstallation?

Edootjuh

Member

Registered: 2011-12-02

Posts: 5

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

I have the same problem, after updating the kernel to 3.1.2 (I think)

The boot screen doesn't show the "waiting for" message, but my kernel line is

kernel /vm-linuz root=/dev/sda1 ro

and adding quiet doesn't work. Is this the same bug or is it just a huge coincidence?

EDIT: it was 3.1.4, and when I try to mount the root partition in the ramfs shell I also get the following:

~> mount /dev/sda1 / -t ext4
modprobe: FATAL: Could not load /lib/modules/3.1.4-1-ARCH/modules.dep

mount: unknown filesystem type 'ext4'

Last edited by Edootjuh (2011-12-02 16:49:16)

SkyTod

Member

Registered: 2009-09-01

Posts: 226

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

Edootjuh, have you read my post? This is the same bug. Here Dave wrote following:

This bug does not apply to you (nor is what you have a bug).

However I'm pretty sure this isn't another bug.

Last edited by SkyTod (2011-12-02 19:54:23)

swanson

Member

From: Sweden

Registered: 2011-02-05

Posts: 759

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

Lucky me I had the LTS kernel installed and quiet at the end of kernel line solved it for the standard kernel!

SkyTod

Member

Registered: 2009-09-01

Posts: 226

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

I fixed it by chrooting and downgrading of kernel.

Edootjuh

Member

Registered: 2011-12-02

Posts: 5

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

@SkyTod: I'd read it but it seemed unlikely to me that it would be entirely unrelated. If I understand correctly, would 'chrooting and downgrading' mean that I boot from the live cd, use chroot to make my current Arch installation root, use downgrader to install a previous kernel version? I'll try that then.

EDIT: I tried it, just using pacman -U and the package cache and now it works again .

Last edited by Edootjuh (2011-12-03 13:44:06)

markhadman

Member

Registered: 2010-10-09

Posts: 39

Re: Cannot Determine Major/Minor for Root partition after kernel upgrade

This problem (https://bugs.archlinux.org/task/27385), is fixed with the latest mkinitcpio (0.8.0-3)