[CentOS-virt] CentOS 6 Xen virt* issues

Mon Sep 28 18:46:21 UTC 2015
Pasi Kärkkäinen <pasik at iki.fi>

On Mon, Sep 28, 2015 at 03:22:10PM +0100, George Dunlap wrote:
> On Sat, Sep 26, 2015 at 7:04 PM, Pasi Kärkkäinen <pasik at iki.fi> wrote:
> > 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.
> 
> That's a bit strange -- maybe there was a post-processing thing added
> to 6.7 that does this, which my package lacks.  I'll take a look at it
> when I get a chance.
> 
> (Or let me know and I'll post the virt-manager source so you can look
> at it and maybe send a pull request!)
> 

Sure :)


> > 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
> 
> 
> Searching around, it looks like the error above is pretty common as a
> first try, but that usually fall-backs are attempted which then
> succeed.  The normal thing following "After open connection callback
> fd=-1" is "DEBUG: Opening direct TCP connection to display at
> 127.0.0.1:5901:-1".
> 
> Can you try virt-viewer -v --debug on 6.6 to see what things look like there?
>

Yep, here's debug output from a working virt-viewer session with virt-viewer 0.6.0-11.el6 (from centos 6.6):

(virt-viewer:3989): virt-viewer-DEBUG: Insert window 0 0x1fba020
(virt-viewer:3989): virt-viewer-DEBUG: fullscreen display 0: 0
(virt-viewer:3989): virt-viewer-DEBUG: connecting ...
(virt-viewer:3989): virt-viewer-DEBUG: Opening connection to libvirt with URI xen://
Opening connection to libvirt with URI xen://
(virt-viewer:3989): virt-viewer-DEBUG: Add handle 7 1 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: initial connect
(virt-viewer:3989): virt-viewer-DEBUG: notebook show status 0x1fc8000
(virt-viewer:3989): virt-viewer-DEBUG: virt_viewer_app_set_uuid_string: UUID changed to ce5bfb10-cd02-7cf2-45b0-7ee36d751987
(virt-viewer:3989): virt-viewer-DEBUG: notebook show status 0x1fc8000
(virt-viewer:3989): virt-viewer-DEBUG: Guest testvm is running, determining display
Guest testvm is running, determining display
(virt-viewer:3989): virt-viewer-DEBUG: Set connect info: (null),(null),(null),-1,(null),(null),(null),0
(virt-viewer:3989): virt-viewer-DEBUG: Guest testvm has a vnc display
Guest testvm has a vnc display
(virt-viewer:3989): virt-viewer-DEBUG: Guest graphics listen '' is NULL or a wildcard, replacing with 'localhost'
(virt-viewer:3989): virt-viewer-DEBUG: Set connect info: localhost,localhost,5901,-1,(null),(null),(null),0
(virt-viewer:3989): virt-viewer-DEBUG: Error operation forbidden: read only access prevents virDomainOpenGraphics
(virt-viewer:3989): virt-viewer-DEBUG: After open connection callback fd=-1
(virt-viewer:3989): virt-viewer-DEBUG: Opening direct TCP connection to display at localhost:5901:-1
Opening direct TCP connection to display at localhost:5901:-1
(virt-viewer:3989): virt-viewer-DEBUG: notebook show status 0x1fc8000
(virt-viewer:3989): virt-viewer-DEBUG: Add timeout 0x2041780 -1 0x7f3436886640 0x203e3a0 1
(virt-viewer:3989): virt-viewer-DEBUG: notebook show status 0x1fc8000
(virt-viewer:3989): virt-viewer-DEBUG: notebook show display 0x1fc8000
(virt-viewer:3989): virt-viewer-DEBUG: notebook show display 0x1fc8000
(virt-viewer:3989): virt-viewer-DEBUG: Display size request 50x50 (desktop 100x100)
(virt-viewer:3989): virt-viewer-DEBUG: Allocated 400x374
(virt-viewer:3989): virt-viewer-DEBUG: Child allocate 374x374
(virt-viewer:3989): virt-viewer-DEBUG: Display size request 50x50 (desktop 100x100)
(virt-viewer:3989): virt-viewer-DEBUG: Allocated 400x374
(virt-viewer:3989): virt-viewer-DEBUG: Child allocate 374x374
(virt-viewer:3989): virt-viewer-DEBUG: desktop resize 1024x768
(virt-viewer:3989): virt-viewer-DEBUG: Preparing main window resize
(virt-viewer:3989): virt-viewer-DEBUG: Decided todo 1024x768 (desktop is 1024x768, fullscreen is 1920x1080
(virt-viewer:3989): virt-viewer-DEBUG: Display size request 1024x768 (desktop 1024x768)
(virt-viewer:3989): virt-viewer-DEBUG: Allocated 1024x768
(virt-viewer:3989): virt-viewer-DEBUG: Child allocate 1024x768
(virt-viewer:3989): virt-viewer-DEBUG: Display size request 50x50 (desktop 1024x768)
(virt-viewer:3989): virt-viewer-DEBUG: Allocated 1024x768
(virt-viewer:3989): virt-viewer-DEBUG: Child allocate 1024x768
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 1 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 2 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 1 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 2 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 1 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 2 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 1 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 2 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 1 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 2 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 1 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Dispatch handler 7 2 0x203dc30
(virt-viewer:3989): virt-viewer-DEBUG: Window closed


So yeah.. here we have the:
(virt-viewer:3989): virt-viewer-DEBUG: Opening direct TCP connection to display at localhost:5901:-1
Opening direct TCP connection to display at localhost:5901:-1

I wonder why the newer virt-viewer version doesn't do/try that anymore.. time to look at the source I guess.
 

>  -George


Thanks,

-- Pasi