[CentOS] User Mode Linux

[Les Mikesell]

On 5/25/2010 3:08 PM, Stephen Harris wrote:
> 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 (2.6.20.7 based kernel)
>
> The writeup is at
>    http://sweh.livejournal.com/362994.html

Good article, but kind of outdated already - and doesn't mention the 
free vmware converter tool to move guests from physical machines to 
vmware or between esxi/server/portable image types which is one of the 
nicer points.  If reinstalling the base OS is an option and you have a 
windows box to run the client, VMware ESXi is a good choice as the host 
even though the free version doesn't give you the nifty cloning features.

-- 
   Les Mikesell
    lesmikesell at gmail.com