[CentOS] User Mode Linux

Tue May 25 20:08:42 UTC 2010
Stephen Harris <lists at spuddy.org>

On Tue, May 25, 2010 at 02:55:27PM -0500, Matt wrote:
> Is anyone using 'user mode linux' to create virtual centos servers
> under a master centos server?  Is there a package for this?  Is xen or
> something a better way to go?

I use it all the time.  I've written a tonne of my own wrapper scripts
to help manage the process and they kinda work.  I can build and deploy
a new server in minutes.  

You need to be careful of UML, though.  The kernel must _not_ allow
loadable modules, otherwise you have no host security at all.  This
may limit it for general purpose stuff.   Performance isn't necessarily
that good, either.

I actually wrote up some basic investigation a couple of months back
where I looked at
   1. RedHat (ahem, sorry, CentOS!) 5.4 64bit Xen
   2. CentOS 5.4 64bit KVM
   3. Citrix XenServer 5.5
   4. VMware ESXi 4.0
   5. VirtualBox 2.2
   6. VMware Server (version unknown)
   7. User Mode Linux ( based kernel)

The writeup is at