[CentOS-virt] CentOS 6 Xen virt* issues

[Pasi Kärkkäinen]

Hello,

I just upgraded some of my el6xen boxes to latest CentOS 6.7, Xen 4.4.3 and dom0 3.18.17 rpms, and noticed these new problems:


1) virt-manager fails to start with an error: "D-Bus library appears to be incorrectly set up; failed to read machine uuid: Failed to open "/var/lib/dbus/machine-id": No such file or directory"

And indeed.. there was no such file. Running command "dbus-uuidgen --ensure" fixed it, and virt-manager starts OK after that. So this was more for the mailinglist archives, if someone else meets the same issue.


2) virt-viewer doesn't work anymore. 

It seems in el6.6 virt-viewer was version 0.6.0-11, but now in el6.7 it's 2.0-7, with a lot of changes..

If I try to use virt-viewer and run "virt-viewer <testvm>" command, I get an error popup dialog saying "Failed to connect: Display can only be attached through libvirt with --attach".

verbose debug output:


# virt-viewer -v --debug -c "xen://" testvm

(virt-viewer:9420): virt-viewer-DEBUG: Set connect info: (null),(null),(null),-1,(null),(null),(null),0
[root at fdell01 rpm]# less testvm01.txt 
(virt-viewer:9374): virt-viewer-DEBUG: connecting ...
(virt-viewer:9374): virt-viewer-DEBUG: Opening connection to libvirt with URI xen://
Opening connection to libvirt with URI xen://
(virt-viewer:9374): virt-viewer-DEBUG: Add handle 7 1 0x865520
(virt-viewer:9374): virt-viewer-DEBUG: initial connect
(virt-viewer:9374): virt-viewer-DEBUG: notebook show status 0x7f0000
(virt-viewer:9374): virt-viewer-DEBUG: virt_viewer_app_set_uuid_string: UUID changed to 587eb1bf-2427-a4d3-9113-d8bfb9911212
(virt-viewer:9374): virt-viewer-DEBUG: No guest-specific fullscreen config, using fallback
(virt-viewer:9374): virt-viewer-DEBUG: notebook show status 0x7f0000
(virt-viewer:9374): virt-viewer-DEBUG: Guest testvm is running, determining display
Guest testvm is running, determining display
(virt-viewer:9374): virt-viewer-DEBUG: Set connect info: (null),(null),(null),-1,(null),(null),(null),0
(virt-viewer:9374): virt-viewer-DEBUG: Guest testvm has a vnc display
Guest testvm has a vnc display
(virt-viewer:9374): virt-viewer-DEBUG: Using direct libvirt connection
(virt-viewer:9374): virt-viewer-DEBUG: Error operation forbidden: read only access prevents virDomainOpenGraphics
(virt-viewer:9374): virt-viewer-DEBUG: After open connection callback fd=-1
(virt-viewer:9374): virt-viewer-DEBUG: Remove handle 1 7
(virt-viewer:9374): virt-viewer-DEBUG: Disposing window 0x7e1820

(virt-viewer:9374): virt-viewer-DEBUG: Set connect info: (null),(null),(null),-1,(null),(null),(null),0


And trying with the "attach" option:

# virt-viewer -v --debug -c "xen://" -a testvm

(virt-viewer:9374): virt-viewer-DEBUG: Set connect info: (null),(null),(null),-1,(null),(null),(null),0
[root at fdell01 rpm]# less testvm02.txt 
(virt-viewer:9389): virt-viewer-DEBUG: connecting ...
(virt-viewer:9389): virt-viewer-DEBUG: Opening connection to libvirt with URI xen://
Opening connection to libvirt with URI xen://
(virt-viewer:9389): virt-viewer-DEBUG: Add handle 7 1 0x13ef580
(virt-viewer:9389): virt-viewer-DEBUG: initial connect
(virt-viewer:9389): virt-viewer-DEBUG: notebook show status 0x137a000
(virt-viewer:9389): virt-viewer-DEBUG: virt_viewer_app_set_uuid_string: UUID changed to 587eb1bf-2427-a4d3-9113-d8bfb9911212
(virt-viewer:9389): virt-viewer-DEBUG: No guest-specific fullscreen config, using fallback
(virt-viewer:9389): virt-viewer-DEBUG: notebook show status 0x137a000
(virt-viewer:9389): virt-viewer-DEBUG: Guest testvm is running, determining display
Guest testvm is running, determining display
(virt-viewer:9389): virt-viewer-DEBUG: Set connect info: (null),(null),(null),-1,(null),(null),(null),0
(virt-viewer:9389): virt-viewer-DEBUG: Guest testvm has a vnc display
Guest testvm has a vnc display
(virt-viewer:9389): virt-viewer-DEBUG: Using direct libvirt connection
(virt-viewer:9389): virt-viewer-DEBUG: Error argument unsupported: fd passing is not supported by this connection
(virt-viewer:9389): virt-viewer-DEBUG: After open connection callback fd=-1
(virt-viewer:9389): virt-viewer-DEBUG: Remove handle 1 7
(virt-viewer:9389): virt-viewer-DEBUG: Disposing window 0x136b820

(virt-viewer:9389): virt-viewer-DEBUG: Set connect info: (null),(null),(null),-1,(null),(null),(null),0



So it seems both connection types/methods now fail.. I'm not sure if the issue is in our custom libvirt build, or in Xen's qemu.. (googling for those errors reveals some related patches which also have patches for qemu: http://comments.gmane.org/gmane.comp.emulators.virt-tools/9185)

Error from the first attempt:

(virt-viewer:9374): virt-viewer-DEBUG: Using direct libvirt connection
(virt-viewer:9374): virt-viewer-DEBUG: Error operation forbidden: read only access prevents virDomainOpenGraphics

Error from the second attempt:
(virt-viewer:9389): virt-viewer-DEBUG: Using direct libvirt connection
(virt-viewer:9389): virt-viewer-DEBUG: Error argument unsupported: fd passing is not supported by this connection



Thanks,

-- Pasi