OL7 Virt-manager console problem

Have you tried installing a VNC server on the OL7 box and accessing virt-manager using VNC? This would at least allow you to determine if it's X in general (if it happens on both the X11-forwarded session and in VNC) or if it's specific to the forwarding to Xming.

I'd also double-check that you have a window manager installed on the OL7 box. On OL6, I used to use xorg-x11-twm (Tiny Window Manager) on machines that I wanted X11 forwarding support. It's not installed by default on a headless/non-GUI machine and without a window manager, X is unable to display non-primary screens, like the console pop-out.

I suggest to keep in mind that X-forwarding is not the same as remote desktop. When you use VNC or remote desktop, all execution and screen output happens on the remote machine. Unlike SSH and X forwarding, where SSH will "wire" the X Window communication back to your client computer. Your X applications on the remote host can still communicate with the local server, which however appears through the SSH tunnel on your client computer, hence communication with the X Window server (Xming) on your local system. So if any X window application works on the local machine, but not under Xming, the problem is most likely Xming or your local PC system. You could perhaps try other X Window servers available for Windows. However, the whole thing does not make sense. If you need access to the console of a virtual machine, simply create a SSH session to it. There is no need to run the virt-manager X Window application from a remote system on your local PC, using your local X Window server.

I had the same problem, in /etc/ssh/sshd_config changed to X11UseLocalhost yes

Solved for me...

I think that does not really make sense though. Apparently virt-manager is opening on the PC side, which means X forwarding is working, but opening the console causes it to break.

Realy, today i was testing and did not work...

What exactly where you testing and what other configurations exist or do not exist that may influence the problem, e.g. IPv6?

(https://bugzilla.novell.com/show_bug.cgi?id=618068)

Here is what the sshd_config man page has to say about the configuration parameter:

So does virt-manager work with X11UseLocalhost=no but the console of a VM works only with X11UseLocalhost=yes. Maybe, but I would rather find this strange and the problem might be something else. Why the OP has X11UseLocalhost=no is another question though.