Hello World,

Recently, I’m encountering some small issues wit the web based VNC Viewer available within the Proxmox VE management interface.  I can launch the vnc viewer and connect to the virtual machine. Howerver, the vnc viewer does not return the full desktop or screen interface.  I can see only a portion of the screen and not the rest.  The web based VNC viewer cannot be resized.

I already mentioned, this issue in a previous post.  Using some workarounds we were able to proceed with the installation and the configuration of the virtual machines.  In some cases, It simply not possible to perform installation or configuration activities because you missing the screen part where you need to click on a button or perform a choice or provide information.  You are stuck !

So far, the only workaround I’ve found here is to install an external VNC viewer client and perform the connection from this vnc client.

This post will try to explain how you can implement this configuration…Ready ? So, let’s go !

Preparing the proxmox VE host

We assume that you have Proxmox VE 2.x installed. I did not try this on previous version so I do not know if this would work.  On the Proxmox VE host, we will need to install the openbsd-inetd package.  In a few words, this package will install a network daemon program that will manage incoming network connections.  The daemon configuration file will allow you to tell which program needs to run when an incoming request is received.  In our situation, installing this package will ensure that the Proxmox VE host listen to incoming VNC incoming requests.

Installing openbsd-inetd package

To install the openbsd-inetd package, you simply type (from the console or using the web “console”) the following command

• aptitude install openbsd-inetd

When prompted, Press Yes to confirm the installation of this package

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Configuring the openbsd-inetd daemon

At this stage, the service is not started because not configured yet.  We will need to modify the inetd configuration file.  For each virtual machine that you want to connect to using the external vnc viewer, you will need to add a entry in the /etc/inetd.conf file using the following structure

<%port>   stream tcp nowait root /usr/sbin/qm qm vncproxy <%vmid%>

• where <%port%> is the port number where the service will listen for incoming requests
• where <%vmid%>  is the id of the virtual machine you want to connect to

In my example, I will need to connect  to the Virtual machine with ID 104 and I will assign the VNC port (where to listen to) to 59004.  You can edit the file and add the following line at the bottom of the configuration file

• 59004 stream tcp nowait root /usr/sbin/qm qm vncproxy 104

Finally, you will need to restart the openbsd-inetd daemon to have the changes applied.  You perform this action by issuing the following command

• /etc/init.d/openbsd-inetd restart

Downloading and installing TigerVNC client

In order to connect to the virtual machine from an external vnc client, the client needs to support authentication.  Well known vnc client such as RealVnc or TightVNC cannot be used in this scenario because they do not support (yet) TLS authentication mechanism.

The Proxmox Wiki mention that a working client would be the TigerVNC. It’s the first time I’ve been used this vnc client and I’m really happy with it. This vnc client will probably be part of my Toolbox kit from now on.

You can download the latest version of the utility here.  Howerver, we recommend you to use the version 1.1.0 because it’s seems to be the most complete and most stable one. When you have download the utility, double-click on the exe (I’m assuming that you have chosen the Windows version) and the installation wizard will start

In the Welcome page, Press Next

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In the license Agreement Page, Accept and Press Next

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 In the Select destination location, accept default or choose a location and press Next

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 In the Start Menu Page, accept default and Press next

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 In the additional tasks, uncheck the checkboxes. We only want to have the vncviewer installed (and not the vncserver part)

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In the Ready to Install page, Press Install

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Wait for the wizard to complete.  In the finish page, you simply press Finish.

To check that you have installed the utility correctly, you can open the start menu and locate the TigerVnc Viewer reference.

To ensure that the Proxmox VE host will be accepting incoming vnc connection, you can perform the following test.  First ensure that your target virtual machine is running and using the telnet client, try to perform a connection to the Proxmox VE host specifying the port you’ve defined in the /etc/inetd.conf file.

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If everything is fine, you should end up with something like this

 

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Connecting to the Virtual machine using  TigerVNC client

Almost there.  We will now try to connect to our virtual machine using the tigervnc client.  Click on the tigerVNC icon in the start menu and you should see the following dialog box displayed.

In the server box, type the name of the proxmox ve host followed by the port to be used (i.e. proxmoxhost:59004)

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Press on the OK button, you might see a message similar to the following. Press yes

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You might then get a prompt similar to the following. You should see this warning only the first time you make the connection. Again Press Yes to confirm your choice

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In the Authentication box, you will need to provide the credentials to perform the connection.  You will use the credentials you use to connect to the Proxmox VE web management interface. Note the format of the user accout, we have used root@pam 

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After a few moment, you should see the vnc console displaying the screen of your virtual machine.  You have succesfully connected to your virtual machine using an external vnc viewer

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Final Words

With Proxmox VE 2.0, it’s possible to connect to your virtual machines using an external vnc client. This is a nice to have feature.  I had to use this method because the web-based vnc viewer was not always working as expected.  The web version cannot be resized and this can be problematic when the console does not display the full deskop.  This is quite annoying. Indeed, I really like the idea to have to manage my proxmox ve infrastructure using only a web browser.  I can perform my job from any machines and I do not need to install any additonal tools.  The fact that the web-based version does not always works give us some limitations.  Let’s hope that this can be fixed in coming releases.

Till Then

See ya