X environment not able to start in DomU, /dev/fb0 missing

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Environment

SUSE Linux Enterprise Server 10 SP1

SUSE Linux Enterprise Server 10
SUSE Linux Enterprise Desktop 10 SP1

SUSE Linux Enterprise Desktop 10

Situation

When updating a DomU to SP1 that was created on SLE10 the graphical output in the virtual machine will not work anymore. When trying to configure the X environment using SaX2 the following messages will appear in/var/log/Xorg.0.log:

(EE) open /dev/fb0: No such file or directory
(EE) No devices detected.

This affects VNC connections to the virtual machine as well.

Resolution

The config file for the DomU in /etc/xen/vm is missing the following entry:

vfb=['type=vnc,vncunused=1']

Once this has been added restart the virtual machine and use SaX2 in runlevel 3 to reconfigure your X environment using:

sax2 -a

to use /dev/fb0 instead of the previous graphics device.

Additional Information

With SP1 for SLE 10 XEN introduced a virtual framebuffer as graphics device where SLE 10 used a different approach.

Disclaimer

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