251
edits
Changes
m
Text replacement - "<htmlet>xen<htmlet>" to "<htmlet>xen</htmlet>"
<table border="0" cellspacing="0" width="100%">
<tr>
<td width="20%">[[Creating and Booting a Xen Guest domainU using an NFS Mounted Root Filesystem|Previous]]<td align="center">[[Xen Virtualization Essentials|Table of Contents]]<td width="20%" align="right">[[Running and Connecting to VNC Servers on a Xen Guest (domainU) System|Next]]</td>
<tr>
<td width="20%">Creating and Booting a Xen Guest domainU using an NFS Mounted Root Filesystem<td align="center"><td width="20%" align="right">Running and Connecting to VNC Servers on a Xen Guest (domainU) System</td>
</table>
<hr>
<htmlet>xen</htmlet>
So far in [[Xen Virtualization Essentials]] we have focused on running Xen domainU systems using just the text based console to interact with the system. It is not uncommon, however, to need to view and interact with a graphical desktop environment running on the guest operating system. This can be achieved using one of two technologies known as SDL and VNC. Probably the most flexible option is that provided by VNC.
In terms of displaying graphical desktop environments for a Xen guest, VNC offers two approaches. The first approach (covered in this chapter) involves using VNC capabilities that are build built into the Xen guest domain (domain0) to view and interact with the virtual frame buffer (vfb) of the domainU system. A second option is to run one or more VNC servers directly on the domainU system and connect directly to those servers. This approach will be covered in the next chapter ([[Running and Connecting to VNC Servers on a Xen Guest (domainU) System]]).
== What is VNC? ==
</pre>
When the gust guest system boots up it will be accessible to the VNC viewer on port 5910 and access will be granted if ''s3cr3t'' is entered at the password prompt.
With the appropriate change made to the configuration file boot the system as usual, being sure to use the -c command-line option so that the text console is also available during the boot process.
</pre>
where ''guestname'' is the name of the domainU guest system. Log in to the domainU guest at the Xen console as a suitable user. Once logged in. , the default desktop environment for the domainU guest system can be launched using the ''startx'' command:
<pre>
</pre>
After a short delay and a number of diagnostic messages in the Xen text console, the graphical desktop environment will appear in the ''vncviewer'' window. The following figure shows a Red Hat Enterprise Linux GNOME desktop running inside the vncviewer window:
[[Image:gnome_desktop_xen_domainU.jpg|GNOME desktop running on a Xen domainU displayed in vncviewer]]
== Establishing a Secure Remote Desktop Session ==
The remote Xen desktop configurations we have explored so far in this chapter are considered to be insecure because no encryption is used. This is acceptable when the remote connection does not extend outside of an internal network protected by a firewall or when the connection is taking place on the Xen host system. When a remote session is required over an internet connection a more secure option is needed. This is achieved by tunneling the remote desktop through a secure shell (SSH) connection.
Before a secure connection is established the SSH server must be installed in the desktop to which the connection is to be established and the firewall configured to allow SSH access. This is the default for many Linux distributions but may not be the case for your distribution. If in doubt refer to the documentation for your chosen distribution to find out how to install and enable SSH access.
If you are connecting to the remote desktop from outside the firewall using Network Address Translation (NAT) keep in mind that the IP address for the ssh connection will be the external IP address provided by your ISP, not the internal LAN IP address of the remote system (since this IP address is not visible to those outside the firewall). You will also need to configure your firewall to forward port 22 (for the ssh connection) to the IP address of the system running the desktop. It is not necessary to forward port 5910. Steps to perform port forwarding differ between firewalls, so refer to the documentation for your firewall, router or wireless base station for details specific to your configuration.
<htmlet>xen</htmlet>
<hr>
<table border="0" cellspacing="0" width="100%">
<tr>
<td width="20%">[[Creating and Booting a Xen Guest domainU using an NFS Mounted Root Filesystem|Previous]]<td align="center">[[Xen Virtualization Essentials|Table of Contents]]<td width="20%" align="right">[[Running and Connecting to VNC Servers on a Xen Guest (domainU) System|Next]]</td>
<tr>
<td width="20%">Creating and Booting a Xen Guest domainU using an NFS Mounted Root Filesystem<td align="center"><td width="20%" align="right">Running and Connecting to VNC Servers on a Xen Guest (domainU) System</td>
</table>
