Enable remote VNC for kvm+qemu

Question

I'm using kvm+qemu on Ubuntu 14.04 Server.

I need to enable VNC for remote hosts, so I edited /etc/libvirt/qemu.conf and uncommented vnc_listen = "0.0.0.0" there.

My problem, is that I don't know how to reload this configuration file without restarting all the hosts. Already tried:

service libvirt-bin reload reload libvirt-bin and killall -HUP libvirtd without success. Is there a way to reload this configuration file? Or do I need to restart all the guests?

Solution

Do not do it in /etc/libvirt/qemu.conf, but rather do it in the definition file for the guest itself, for example in /etc/libvirt/qemu/serv64_dev.xml. here is an example of the relevant section:

<graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0'>
  <listen type='address' address='0.0.0.0'/>
</graphics>
<video>
  <model type='vmvga' vram='9216' heads='1'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
</video>

Use virsh edit domain name to edit, example virsh edit serv64_dev (from any directory), as it does some additional checks upon exit.

The default editor used by virsh edit is as defined by the $EDITOR environment variable, or VI if it does not exist. add export EDITOR="/bin/nano" to your ~/.bashrc file to set, for example, nano as your default editor.

Comments

[pgb]

Done, but still I can't connect (nor telnet to port 5904, which is the one assigned to that VM)

[Doug Smythies]

I would have expected it to be on port 5900, unless there are already 4 others that started before it.

[pgb]

It's the fourth VM, virsh vncdisplay MyVM reports :4. In any case, all ports from 5900 to 5904 are unaccessible through telnet...

[Doug Smythies]

And you are attempting to connect to the host IP address port 5904, right? Then, I am out of ideas, as I have only ever made my VM's with VNC support to start with. If you think it will help, I can post my entire .xml file.

[pgb]

Yes, host IP address. Don't worry posting the entire xml, I'll try changing qemu.conf and see if that helps.

[Doug Smythies]

O.K., Please post back how you make out. By the way, I have never edited qemu.conf

[Doug Smythies]

Do you have a firewall (iptables or ufw or ?) blocking access to those ports?