Re: [Xen-users] New domains do not show up with "xm list"

[Felix Kuperjans <felix@xxxxxxxxxxxxxxxxxx>]

You have to distinguish virtual and real devices properly:

The devices you are seeing in you Domain-0 (the output of ls -l /dev/disk/by-id/) are the real physical devices. The VM will have its own *virtual* devices, which are either based on a physical device (which changes its name then) or for example on a file in the host's filesystem. The root option is passed to the *virtual* kernel and needs to state the *virtual* name of the device (to begin with, its easiest to call it xvda1, this will make it easier to distinguish). In the disk = [ ... ] option, you map the virtual device to a real one (or a file, ...). The line ist the following:
disk = [ "phy:/dev/sda2,xvda1,w" ]
If you like the *real* device sda2 to be the first and only virtual device of the VM.
The root option must be /dev/xvda1 then, of course.

But still you'd need:
1. An operating system installed in /dev/sda2
2. If you need the initramdisk which you specified in your disk option, you must pass it with ramdisk="path to ramdisk in Domain-0" to the VM

Try reading some Howtos on setting up Xen VMs or buy a book about Xen.

Regards,
Felix

Am 29.09.2010 22:44, schrieb Priya:

Hey guys!

So the entire output of "xm create -c <domU.cfg> is in attachment. The part that is showing the issue is towards the end:

VFS: Cannot open root device "hda1" or unknown-block(0,0)

Please append a correct "root=" boot option; here are the available partitions:

ca00           59997 xvda driver: vbd

Following is the output of my disks by id:

root@XenOpen:/boot# ls -l /dev/disk/by-id/

total 0

lrwxrwxrwx 1 root root  9 2010-09-29 10:31 ata-WDC_WD3200AAKS-75L9A0_WD-WMAV28284320 -> ../../sda

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 ata-WDC_WD3200AAKS-75L9A0_WD-WMAV28284320-part1 -> ../../sda1

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 ata-WDC_WD3200AAKS-75L9A0_WD-WMAV28284320-part2 -> ../../sda2

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 ata-WDC_WD3200AAKS-75L9A0_WD-WMAV28284320-part5 -> ../../sda5

lrwxrwxrwx 1 root root  9 2010-09-29 10:31 scsi-SATA_WDC_WD3200AAKS-_WD-WMAV28284320 -> ../../sda

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 scsi-SATA_WDC_WD3200AAKS-_WD-WMAV28284320-part1 -> ../../sda1

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 scsi-SATA_WDC_WD3200AAKS-_WD-WMAV28284320-part2 -> ../../sda2

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 scsi-SATA_WDC_WD3200AAKS-_WD-WMAV28284320-part5 -> ../../sda5

lrwxrwxrwx 1 root root  9 2010-09-29 10:31 wwn-0x50014ee0ac054885 -> ../../sda

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 wwn-0x50014ee0ac054885-part1 -> ../../sda1

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 wwn-0x50014ee0ac054885-part2 -> ../../sda2

lrwxrwxrwx 1 root root 10 2010-09-29 10:31 wwn-0x50014ee0ac054885-part5 -> ../../sda5

I changed the "hda1" to "sda2" in my cfg file, so now it looks like this:

kernel = "/boot/vmlinuz-2.6.32.21-xen"

memory = 128

name = "MyLinux"

root = "/dev/sda2 ro"

disk = [ "file:/boot/initrd.img-2.6.32.21-xen,hda1,w" ]

And now when I do "xm create" I get:

root@XenOpen:/etc/xen# xm create -c mylinux.cfg 

Using config file "./mylinux.cfg".

Started domain MyLinux (id=14)

Domain has already finished

Could not start console

And still no addition to "xm list" obviously!... What's the correct value that I should use for the "root" parameter?

The contents of /etc/fstab are:

root@XenOpen:/boot# cat /etc/fstab 

# /etc/fstab: static file system information.

#

# Use 'blkid -o value -s UUID' to print the universally unique identifier

# for a device; this may be used with UUID= as a more robust way to name

# devices that works even if disks are added and removed. See fstab(5).

#

# <file system> <mount point>   <type>  <options>       <dump>  <pass>

proc            /proc           proc    nodev,noexec,nosuid 0       0

# / was on /dev/sda1 during installation

UUID=44f6c489-7214-4402-a71b-1b70f6031acf /               ext4    errors=remount-ro 0       1

# swap was on /dev/sda5 during installation

UUID=e4e47af4-4513-4557-a802-e71bcebe9395 none            swap    sw              0       0

Thanks!

On Wed, Sep 29, 2010 at 4:23 PM, Egberto Monteiro <egbertomonteiro@xxxxxxxxx> wrote:

Try "xm create -c <domu.cfg>" and show us what occured.

Att,
Egberto Monteiro


Em 09/29/2010 05:08 PM, Priya escreveu:

Hello people!

This is a strange error and I am sure I am missing something really basic. I installed Xen 4.0.1 on Ubuntu 10.04, and only have command line access to my domain-0.

Every thing seems to be working okay. My "xm info" output is as follows:

--------------------

root@XenOpen:/etc/xen# xm info

host                   : XenOpen

release                : 2.6.32.21-xen

version                : #2 SMP Mon Sep 27 10:23:06 EDT 2010

machine                : x86_64

nr_cpus                : 2

nr_nodes               : 1

cores_per_socket       : 2

threads_per_core       : 1

cpu_mhz                : 2992

hw_caps                : bfebfbff:20100800:00000000:00000940:0408e3fd:00000000:00000001:00000000

virt_caps              : 

total_memory           : 3931

free_memory            : 3048

node_to_cpu            : node0:0-1

node_to_memory         : node0:3048

node_to_dma32_mem      : node0:2984

max_node_id            : 0

xen_major              : 4

xen_minor              : 0

xen_extra              : .1

xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p 

xen_scheduler          : credit

xen_pagesize           : 4096

platform_params        : virt_start=0xffff800000000000

xen_changeset          : unavailable

xen_commandline        : dummy=dummy dom0_mem=832M

cc_compiler            : gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5) 

cc_compile_by          : root

cc_compile_domain      : 

cc_compile_date        : Mon Sep 27 11:36:56 EDT 2010

xend_config_format     : 4

_________________

I tried to create PV domains using the following configuration file:

root@XenOpen:/etc/xen# more mylinux.cfg 

kernel = "/boot/vmlinuz-2.6.32.21-xen"

memory = 128

name = "MyLinux"

root = "/dev/hda1 ro"

disk = [ "file:/boot/initrd.img-2.6.32.21-xen,hda1,w" ]

The problem is that when I try to create new PV domains, I get a message saying that they have been created but they don't show up when I do a subsequent xm list:

root@XenOpen:/etc/xen# xm create mylinux.cfg 

Using config file "./mylinux.cfg".

Started domain MyLinux (id=11)

root@XenOpen:/etc/xen# xm list

Name                                        ID   Mem VCPUs      State   Time(s)

Domain-0                                     0   832     2     r-----    151.2

Could someone please throw some light on what in the world is going on...please!

--
Priya Bhat

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--
Priya Bhat

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