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I have a Xen 4.1 installation on Debian Wheezy, administered through xm. When I boot a Jessie DomU I get output on the emulated VGA card / VNC display only for the first few seconds of boot, then it stops.

dmesg shows:

[   30.968257] xenbus_probe_frontend: Timeout connecting to device: device/vkbd/0 (local state 3, remote state 1)
[   30.968336] xenbus_probe_frontend: Timeout connecting to device: device/vfb/0 (local state 3, remote state 1)`

Which to my understanding means, that the backend part of the pv driver is not initialised.

Relevant DomU config:

device_model    = '/usr/lib/xen/bin/qemu-dm' 
boot            = "dc"
sdl             = 0 
vnc             = 1 
vncconsole      = 0 
vnclisten       = "0.0.0.0" 
vncpasswd       = redacted 
serial          = 'pty' 
usbdevice       = 'tablet' 
vncdisplay      = 1737 
keymap          = 'de'

I tried adding a vfb= line since the documentation is somewhat unclear wether the above options create a vfb device or only an emulated VGA card. This didn't help.

Backend (xenstore in Dom0) shows:

domain = "root1194.c.artfiles.de"
vnc = "1"
xauthority = "/root/.Xauthority"
vnclisten = "0.0.0.0"
vncdisplay = "1737"
frontend = "/local/domain/85/device/vfb/0"
vncpasswd = "redacted"
state = "1"
keymap = "de"
online = "1"
frontend-id = "85"
uuid = "688c4f1e-4b8b-6273-c243-4c2f21d48c4b"
location = "0.0.0.0:7637"

State 1 means "XenbusStateInitialising" as far as I see from the docs. So I'm expecting a problem in the Dom0 to be the cause of the problems.

Any Idea what it could be?

HBruijn
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tim
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1 Answers1

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I encountered the exact same problem with Debian Jessie on XEN HVM where GRUB appeared on the VNC console but all output ceased shortly after boot began. The solution that worked for me was to reconfigure GRUB (in DomU) to disable the framebuffer and request VGA output.

My steps were as follows:

  1. Modify /etc/default/grub so that the following two lines are present:

    GRUB_CMDLINE_LINUX_DEFAULT="quiet fb=false"  
GRUB_GFXPAYLOAD_LINUX="keep"

  2. Regenerate the GRUB files

    update-grub2
  3. Reboot the machine and the console should now appear
Justin G.
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