Arch Linux

vis

Member

From: Switzerland

Registered: 2007-02-25

Posts: 81

Root device doesn't exist after complete upgrade

Did a fresh install from 2010.05-core-i686 x86_64 on this laptop, only the basic system. It worked with kernel parameter "nomodeset". But after a "pacman -Syu" it breaks:
udev: starting version 158
done.
:: Running Hook [udev]
:: Triggering uevents...done
Waiting 10 seconds for device /dev/sda2 ...
Root device '/dev/sda2' doesn't exist. Attempting to create it.
ERROR: Unable to determine major/minor number of root device '/dev/sda2'
You are being dropped to a recovery shell
...

The fallback option on Grub works. Both have the same kernel,
kernel /boot/vmlinuz26 root=/dev/sda2 ro nomodeset
but different initrd
/boot/kernel26.img resp. kernel26-fallback.img

uname -a
Linux x201 2.6.34-ARCH #1 SMP PREEMPT Sat Jun 19 00:07:49 CEST 2010 x86_64 ...

The hardware is Lenovo x201 brand new.

Would making a new initrd solve the problem? How?

vis

Member

From: Switzerland

Registered: 2007-02-25

Posts: 81

Re: Root device doesn't exist after complete upgrade

Found a solution, still need an explanation though.

I made a new initrd
# cd /boot
# mkinitcpio -g kernel26b.img

Put this initd in /boot/grub/menu.list, and it comes up.

Can somebody explain me, what has happened?

These are the sizes of initrd in bytes:
kernel26.img 1592462
kernel26b.img 1599225
kernel26-fallback.img 8325258

hungerfish

Member

Registered: 2009-09-13

Posts: 254

Re: Root device doesn't exist after complete upgrade

I can't explain to you what has happened, but I can tell you that I've now had the same problem twice, one on 64bit, once on 32bit.
My solution was also to rebuild the initrd (painfully via live-cd) and then it just worked again.

EDIT:
Obviously, the initrd image was missing the filesystem stuff, but why it did not get included, I do not know.

Last edited by hungerfish (2010-07-02 12:31:22)

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Beetles and bacteria are vastly more successful than humans in terms of survival.

hokasch

Member

Registered: 2007-09-23

Posts: 1,461

Re: Root device doesn't exist after complete upgrade

Can you double-check the pacman log if the initrd generation was succesfull when the kernel was updated? Another thing to check would be if you merged the config files after an mkinitcpio update installed a new /etc/mkinitcpio.conf.

w1ntermute

Member

Registered: 2009-06-28

Posts: 146

Re: Root device doesn't exist after complete upgrade

This just happened to me on a fresh net install of x86_64, it's probably a bug in one of the recently updated packages. Could it be device-mapper?

Edit: followed this procedure to fix the problem.

Last edited by w1ntermute (2010-07-02 21:16:06)

vis

Member

From: Switzerland

Registered: 2007-02-25

Posts: 81

Re: Root device doesn't exist after complete upgrade

pacman wrote these lines during upgrade:
...
:: Generating image '/boot/kernel26.img' ...SUCCESS
==> SUCESS
...
:: Generating image '/boot/kernel26-fallback.img' ...SUCCESS
==> SUCESS
upgraded kernel26 (2.6.33.4-1 -> 2.6.34-2)
...

enihcam

Member

From: Internet

Registered: 2009-12-20

Posts: 222

Re: Root device doesn't exist after complete upgrade

I got the same problem also..
SiS 741GX
Seagate IDE 40GB

The solutions above did not work...

Last edited by enihcam (2010-07-04 02:29:01)

w1ntermute

Member

Registered: 2009-06-28

Posts: 146

Re: Root device doesn't exist after complete upgrade

I'm still having the problem too, the issue was only fixed for one boot. I was hoping that the updated kernel26 and util-linux-ng packages would fix this problem, but I guess not.

vis

Member

From: Switzerland

Registered: 2007-02-25

Posts: 81

Re: Root device doesn't exist after complete upgrade

I know, this is only a workaround. But I don't understand why it should not work:

# vi /etc/mkinitcpio.conf
HOOKS="base udev autodetect pata scsi sata filesystems"
# ^the original, haven't changed anything

# cd /boot
# mkinitcpio -g kernel26b.img

# vi /boot/grub/menu.lst
....
title Arch Linux
root (hd0,1)
#      ^^^^^^^ will be different for you
kernel /boot/vimlinuz root=/dev/sda2 ro
#                                            ^^^^^^^^ will be different
initrd /boot/kernel26b.img
...

# reboot

w1ntermute

Member

Registered: 2009-06-28

Posts: 146

Re: Root device doesn't exist after complete upgrade

Which partitions ("/" or "/boot") are "root (hd0,1)" and "root=/dev/sda2" supposed to point to? It looks like both are "/", is that correct?

Hyugga

Member

From: Santiago, Chile

Registered: 2010-03-26

Posts: 335

Re: Root device doesn't exist after complete upgrade

I have the same problem with no solution yet, i posted it some time ago: http://bbs.archlinux.org/viewtopic.php? … 59#p788159
I hope something of that works for you, butit didn't work for me.

Last edited by Hyugga (2010-07-08 03:41:57)

w1ntermute

Member

Registered: 2009-06-28

Posts: 146

Re: Root device doesn't exist after complete upgrade

I think it's an issue specific to certain hardware. I was able to do a clean install in a 32-bit VirtualBox VM, but I tried doing clean installs on a physical machine before and after that, and it failed both times. At first I thought it might be a 64-bit specific problem, but I'm running 64-bit Arch on my laptop, and I'm up-to-date with no problems.

Maybe it's an issue with just new 64-bit installs, but hungerfish reported an issue with 32-bit as well, so I'm really confused.

Last edited by w1ntermute (2010-07-08 21:51:16)

Hyugga

Member

From: Santiago, Chile

Registered: 2010-03-26

Posts: 335

Re: Root device doesn't exist after complete upgrade

I have 32-bit arch...So...

w1ntermute

Member

Registered: 2009-06-28

Posts: 146

Re: Root device doesn't exist after complete upgrade

mkinitcpio-busybox has been updated, so maybe that will fix the problem.