This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-users] Problem with VNC Console on Paravirtualization VMs

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-users] Problem with VNC Console on Paravirtualization VMs
From: David Goldsmith <dgoldsmith@xxxxxxxx>
Date: Thu, 08 Feb 2007 14:03:33 -0500
Delivery-date: Thu, 08 Feb 2007 11:03:26 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird (Windows/20061207)
Hash: SHA1

I am running Xen on CentOS 4.4 for the host.  I am testing both
full virtualization and para-virtualization VMs.

Full Virtualization
I have a full virtualization VM running CentOS 4.4 using the following
key elements from the config file

kernel = '/usr/lib/xen/boot/hvmloader'
device_model = '/usr/lib/xen/bin/qemu-dm'
sdl = 0
vnc = 1
nographic = 0

When I start this VM with 'xm create', the qemu-dm process sets up a
network listener on TCP port 5900.  I can run vncviewer from my laptop
and connect to port 5900 on the Xen host and I get connected to the
'HVMXEN-<name>' console for my VM.  With this, I can use Alt-F# to jump
between the 6 virtual console that Linux provides.  If I run 'xm console
<vmid>' to try to connect to the HVM host, I get the error 'xenconsole:
Could not read tty from store: No such file or directory'

Should I be able to use 'xm console ...' to connect to an HVM VM?

I am using the CentOS 4.4 image from jailtime.org.  The default config
for this image was:

kernel = "/boot/vmlinuz-2.6.9-xenU"
memory = 128
name = "centos.4-4"
vif = [ '' ]
dhcp = "dhcp"
disk = ['file:/data2/xenimages/centos.4-4.img,sda1,w',
root = "/dev/sda1 ro"

I have experimented with adding various vnc, vnclisten and vncviewer
options to the config file.

If I have only 'vnc = 1', then after I create the VM, I can run 'xm
console <vmid>' and I get connected to a pseudo-console.  I see the
equivalent of tty1 but cannot toggle between the six virtual consoles
that appear to be running.

With only 'vnc = 1', I also have no network listeners on ports 55xx or
59xx so I can not connect to the VM with vncviewer.

If I add 'vncviewer = 1' to the config file and try to create the VM, I
get the following output/error:

  # xm create centos.4-4.xen3.cfg
  Using config file "./centos.4-4.xen3.cfg".
  VNC= 1
  Error: Unable to connect to xend: Name or service not known. Is
  xend running?

The VM does not start, but a vncviewer process was started that is
listening on TCP port 5501.

  vncviewer -log *:stdout:0 -listen 5501

If I remove 'vncviewer = 1' and add 'vnclisten = <my IP>', then I can
start the VM but have no network listeners on any 55xx/59xx ports. I can
use 'xm console <vmid>' to connect to the console.

Should I be able to use a vncviewer to connect to the full console on a
paravirtualized VM?  And if so, what are the necessary config file
settings and external setting with regard to the vncserver/vncviewer?

David Goldsmith
Version: GnuPG v1.4.3rc2 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org


Xen-users mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • [Xen-users] Problem with VNC Console on Paravirtualization VMs, David Goldsmith <=