Arch Linux

Llama

Banned

From: St.-Petersburg, Russia

Registered: 2008-03-03

Posts: 1,379

Booting from a USB drive [SOLVED]

Hi,

I've got a hard drive with an old installation of Arch (migration leftover). I've put the drive into a USB carrier and tried to boot from it.

It ends up with kernel not quite loaded:

Root device '/dev/disk/by-label/Root' doesn't exist. Attempting to create it.
ERROR: Unable to determine major/minor number of root device '/dev/disk/by-label/Root'

/boot/grub/menu.lst:

# (0) Arch Linux
title  Arch Linux (USB Box)
root   (hd0,1)
kernel /boot/vmlinuz26 root=/dev/disk/by-label/Root ro
initrd /boot/kernel26.img

/etc/fstab:

/dev/disk/by-label/Swap swap swap defaults 0 0
/dev/disk/by-label/Root / ext4 defaults 0 1
/dev/disk/by-label/Home /home ext4 defaults 0 1

Tried

# mkinitcpio -p kernel26

using chroot: no difference. 'Root' is a unique label, not to be found on other drives.

Any ideas?

Last edited by Llama (2010-03-25 16:22:14)

Ber

Member

From: Belgium

Registered: 2006-07-05

Posts: 80

Website

Re: Booting from a USB drive [SOLVED]

Try figuring out which partition is labeled "Root", and change your root= kernel option to "root=/dev/sda1" or whatever you previously found.

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V=RI sweet V=RI

Llama

Banned

From: St.-Petersburg, Russia

Registered: 2008-03-03

Posts: 1,379

Re: Booting from a USB drive [SOLVED]

Try figuring out which partition is labeled "Root", and change your root= kernel option to "root=/dev/sda1" or whatever you previously found.

root=/dev/sda2 .

This way I booted nicely and uneventfully into my new installation (new HDD on SATA)

root=/dev/sdb2  led me exactly into the same place as 'Root' label did. Which is consistent enough, IMHO. I would still like to know what am I supposed to do about it .

Ber

Member

From: Belgium

Registered: 2006-07-05

Posts: 80

Website

Re: Booting from a USB drive [SOLVED]

This is consistent, but not automatic (all my partitions aren't accessible through labels)

It might seem obvious, but have you included the "usb" hook in your initcpio?

Last edited by Ber (2010-03-25 15:25:20)

---

V=RI sweet V=RI

Llama

Banned

From: St.-Petersburg, Russia

Registered: 2008-03-03

Posts: 1,379

Re: Booting from a USB drive [SOLVED]

It might seem obvious, but have you included the "usb" hook in your initcpio?

From now on it's going to be obvious even for the likes of me

/etc/mkinitcpio.conf:

HOOKS="base udev autodetect pata scsi sata usb filesystems"

Then

(1) Change root: http://wiki.archlinux.org/index.php/Chroot

(2) Rebuild the kernel image:

# mkinitcpio -p kernel26

That's it. Labels won't hurt .

Thank you, Ber!

Last edited by Llama (2010-03-25 16:21:33)