Subject: Image-based Linux-DomUs fail to boot ("VFS: Cannot open root device "hda1" or unknown-block(0,0)")
To: None <port-xen@netbsd.org>
From: Mark Weinem <mark.weinem@onlinehome.de>
List: port-xen
Date: 08/03/2006 17:39:32
Hi,
Thanks to community efforts there are now many ready-to-use VM-Images
available, to "kickstart" Linux-DomUs. Just for examples:
http://www.xen-get.org/
http://cdprojekte.mattiasschlenker.de/Public/Xen-Images/
But unfortunately I don't get them run with Xen3/NetBSD-3.99.21
I tried the following three methods without luck.
1) Copying a Linux system over to a ext2 filesystem (created by NetBSD):
- I started "disklabel -i" and changed "fstype" of /dev/wd0g
from "4.2BSD" to "Linux Ext2"
- "mke2fs /dev/wd0g"
- "mount_ext2fs /dev/wd0g /mnt" , "cp -R /linux_files/ /mnt/"
and my config file for the Linux domU:
kernel = "/vmlinuz-2.6.16.13-xen"
memory = 300
name = "suse"
vif = [ 'bridge=bridge0' ]
disk = [ 'phy:/dev/wd0g,0x301,w' ]
root = "/dev/hda1 rw"
The corresponding error message after "xm create ..."
-----
VFS: Cannot open root device "hda1" or unknown-block(0,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(0,0)
-----
2) Booting a file-based Linux image directly:
- the config file for the Linux domU:
kernel = "/vmlinuz-2.6.16.13-xen"
memory = 300
name = "suse"
vif = [ 'bridge=bridge0' ]
disk = [ 'file:/usr/xen/linux_hda1.img,0x301,w' ]
root = "/dev/hda1 rw"
ends with the same error message:
-----
VFS: Cannot open root device "hda1" or unknown-block(0,0)
[...]
-----
3) Using "vnd" to integrate "linux_hda1.img"
- "vnconfig -u vnd0"
- "vnconfig -c vnd0 linux_hda1.img"
- the config file for the Linux domU:
kernel = "/vmlinuz-2.6.16.13-xen"
memory = 300
name = "suse"
vif = [ 'bridge=bridge0' ]
disk = [ 'phy:/dev/vnd0,0x301,w' ]
root = "/dev/hda1 rw"
- error message:
-----
"Device 769 (vbd) could not be connected. Hotplug scripts not working"
-----
The system runs 2x NetBSD-3.01 domUs and one Ubuntu Linux domU (from an
ordinary installation via CD) without such problems.
Greetings, Mark Weinem
-