[CentOS] virtualization on the desktop a myth, or a reality?

Wed Mar 2 19:46:20 UTC 2011
David Sommerseth <dazo at users.sourceforge.net>

On 02/03/11 19:07, Les Mikesell wrote:
> On 3/2/2011 11:29 AM, Rudi Ahlers wrote:
>> So, I installed CentOS + KDE, chose the Virtualization package and
>> used Virtual Machine Manager to setup another CentOS VM inside CentOS
>> (I only have a CentOS ISO on this SAN, since we don't use Debian /
>> Slackware / FC / Ubuntu / etc). The installation was probably about
>> the same speed as it would be on raw hardware. But, using the
>> interface is painfully slow. I opened up Firefox and browsed the web a
>> bit. The mouse cursor lagged a bit and whenever I loaded a slow /
>> large website, it seemed asif the whole VM lagged behind.
> X without hardware acceleration is pretty ugly - you end up making the 
> CPU do block moves even for simple things like screen scroling.  Not 
> sure how how the virtual interface works, but a better approach is 
> either running X natively on your local hardware with the desktop/app 
> remote (if you are on a low latency LAN) or freenx on the server and the 
> NX client locally (works regardless of the connection speed).

What about making the VM running X server, accepting TCP connections, and
access the VM from your host using a "local" X client display.  A lot of
bad things can be said about the X network protocol, but at least it works
smoother than VNC.  The X protocol requires bandwidth (compared to VNC),
but working against a virtual network adapter doesn't necessarily kill the

Other than that, SPICE is probably the future [1] on Linux.  That should
slowly begin to be useful in RHEL5, RHEL6 and Fedora 14, if I'm not much
mistaken.  Not sure how much is implemented in RHEL5/CentOS5 though.
However, for SPICE to work, you need to use KVM.  And you need the qemu-kvm
part to initialise the SPICE display properly as well.

kind regards,

David Sommerseth

[1] <http://www.youtube.com/watch?v=S4DZwYqnyJM>