Arch Linux

Lockheed

Member

Registered: 2010-03-16

Posts: 1,521

Can't boot after installing from existin linux

I installed Arch from Ubuntu and everything went rather fine. I was even able to login to Arch bash while in Ubuntu and install some packets with pacman.

However, when I try to boot arch, I am getting Kernel panic:

No filesystem could mount root, tried:
Kernel panic - not syncing: VFS: unable to mount root fs on unknown-block(0,0)
Pid: 1, comm: swapper Not tainted

This is my fstab:

# 
# /etc/fstab: static file system information
#
# <file system>        <dir>         <type>    <options>          <dump> <pass>
proc /proc proc defaults 0 0
devpts                 /dev/pts      devpts    defaults            0      0
shm                    /dev/shm      tmpfs     nodev,nosuid        0      0

/dev/cdrom             /media/cd   auto    ro,user,noauto,unhide   0      0
/dev/dvd               /media/dvd  auto    ro,user,noauto,unhide   0      0
/dev/fd0               /media/fl   auto    user,noauto             0      0

UUID=80e927bf-4871-4d1b-9953-45d5b0ad9868 / ext4 nodev,nosuid,noatime 0 2
UUID=b0d53a94-e988-4860-ab15-95e75be2d71b /home ext4 nodev,nosuid,noatime 0 2
UUID=087b9e3b-a65c-4890-9b0e-de019b0fff18 /media/ubuntu ext4 relatime,errors=remount-ro 0 1,noatime,nodiratime
UUID=24e59dc5-cd67-4717-94ed-c3ff28b6ab26 none swap defaults 0 0
UUID=a074cd66-2d9b-474d-8be8-e778fa7ad613 /media/agora ext2 defaults 0 2
/dev/sda1 /media/c ntfs-3g defaults,locale=pl_PL.utf8 0 0

Lockheed

Member

Registered: 2010-03-16

Posts: 1,521

Re: Can't boot after installing from existin linux

Help, please.

hokasch

Member

Registered: 2007-09-23

Posts: 1,461

Re: Can't boot after installing from existin linux

There is something wrong with your grub config. Arch uses grub legacy, newer ubuntu grub2.

Also check this posts:
http://bbs.archlinux.org/viewtopic.php?id=92525
http://bbs.archlinux.org/viewtopic.php?pid=686258

Lockheed

Member

Registered: 2010-03-16

Posts: 1,521

Re: Can't boot after installing from existin linux

I read those threads, but only one offers some kind of soultion and I think I already tried something similar.

On ubuntu, I am using Grub2. I also installed Grub2 on Arch and once it gave me this kernel panic, I replaced grub.cfg in Arch with the one from Ubuntu (which is working just fine if I boot Ubuntu or XP) but it made no difference whatsoever.

Here's my grub.cfg:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by /usr/sbin/update-grub using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
set default=0
set timeout=3
set root=(hd0,6)
search --fs-uuid --set 087b9e3b-a65c-4890-9b0e-de019b0fff18
if font /usr/share/grub/ascii.pff ; then
  set gfxmode=640x480
  insmod gfxterm
  insmod vbe
  terminal gfxterm
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=cyan/blue
set menu_color_highlight=white/blue
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_hurd ###
### END /etc/grub.d/10_hurd ###

### BEGIN /etc/grub.d/40_custom ###
# This file is an example on how to add custom entries
menuentry "Ubuntu, linux 2.6.32.9-newyork" {
    linux    /boot/vmlinuz-2.6.32.9-newyork root=UUID=087b9e3b-a65c-4890-9b0e-de019b0fff18 ro  quiet splash
    initrd    /boot/initrd.img-2.6.32.9-newyork
}
menuentry "Arch" {
    set root=(hd0,9)
    linux /boot/vmlinuz26 root=/dev/sda9
}
menuentry "XP x64" {
    set root=(hd0,1)
    chainloader +1
}
### END /etc/grub.d/40_custom ###

It is the only file in /boot/grub/ which seems strange, as the same folder in Ubuntu contains loads of other files, too.

hokasch

Member

Registered: 2007-09-23

Posts: 1,461

Re: Can't boot after installing from existin linux

I read those threads, but only one offers some kind of soultion and I think I already tried something similar.

In this post someone describes a solution that worked for him, after getting the exact same error with grub2 from Ubuntu...

You do not need grub installed two times. Grub2 from ubuntu can load archlinux fine, if the syntax is right.
If you installed the second grub2 from arch into mbr, all config must now be done in arch's grub.

Looking at you grub.cfg - the arch entry is missing an initramfs line, and you should use root=/dev/disk/by-uuid instead of /dev/sda.
http://wiki.archlinux.org/index.php/GRUB2

Last edited by hokasch (2010-05-10 14:40:40)

tomk

Forum Fellow

From: Ireland

Registered: 2004-07-21

Posts: 9,839

Re: Can't boot after installing from existin linux

Reinstall grub.

skunktrader

Member

From: Brisbane, Australia

Registered: 2010-02-14

Posts: 1,543

Re: Can't boot after installing from existin linux

The version of grub2 that you are using is generating an incorrect entry for Arch during /etc/grub.d/30_os-prober.

You need to edit the entry for Arch and include the line

initrd /boot/kernel26.img

To make the change "stick", you can edit /etc/grub.d/40_custom and add entries for Arch and Arch Fallback
For example, my /etc/grub.d/40_custom contains the following

menuentry "ArchLinux (on /dev/sda8)" {
        insmod ext2
        set root=(hd0,8)
        search --no-floppy --fs-uuid --set 1d88233e-5f1d-4fbd-8718-bdab2f7f6ca4
        linux /boot/vmlinuz26 root=/dev/sda8 ro vga=834
        initrd /boot/kernel26.img
}
menuentry "ArchLinux Fallback (on /dev/sda8)" {
        insmod ext2
        set root=(hd0,8)
        search --no-floppy --fs-uuid --set 1d88233e-5f1d-4fbd-8718-bdab2f7f6ca4
        linux /boot/vmlinuz26 root=/dev/sda8 ro vga=834
        initrd /boot/kernel26-fallback.img
}

You will obviously need to modify the uuids and /dev/sdax to suit your installation

skunktrader

Member

From: Brisbane, Australia

Registered: 2010-02-14

Posts: 1,543

Re: Can't boot after installing from existin linux

Don't forget you will to run

sudo update-grub

after updating any of the config files

Lockheed

Member

Registered: 2010-03-16

Posts: 1,521

Re: Can't boot after installing from existin linux

Don't forget you will to run

sudo update-grub

after updating any of the config files

Well, I followed your suggestions and modified grub.cfg accordingly. However, the result is that now it won't even start booting Arch. Immediately, I am getting

error: file not found.

Lockheed

Member

Registered: 2010-03-16

Posts: 1,521

Re: Can't boot after installing from existin linux

If my partition is ext4, do I still need to use

insmod ext2

?

--------
EDIT:

It had to be etc2. It works now.

Last edited by Lockheed (2010-05-14 11:55:46)