[nzlug] VMware x Xen x KVM x Qemu

[Michael Hutchinson]

> -----Original Message-----
> From: nzlug-bounces at linux.net.nz [mailto:nzlug-bounces at linux.net.nz]
On
> Behalf Of Papalagi Pakeha
> Sent: Wednesday, 2 April 2008 2:56 p.m.
> To: NZLUG Mailing List
> Subject: [nzlug] VMware x Xen x KVM x Qemu
> 
> Hi guys,
> 
> I'm playing with virtualization to get a better understanding of the
> many technologies now available for linux. And I wonder what are your
> favourites and why?
> 
> So far I got these impressions:
> 
> VMware Server
> + installation is no brainer and the interface is very user friendly
> - networking is magic, it creates some vmnet interfaces and does NAT
> on them automagically which makes it hard to impossible to use
> standard iptables NAT and stuff on it.
> - vmware-tools don't install in Ubuntu Hardy but that could be because
> my Hardy DVD the beta one.
> - client sw is needed on the remote side but there's a linux version
> so it's not that bad.
> 
> Xen in CentOS 5
> + comes bundled with the system - that's good for updates and support
> - I couldn't make graphical console running over the network (got only
> black screen) but works fine on the server locally. That makes it hard
> to use on remote servers and also means that the server must have
> X.org running.
> - Win XP failed to install even though my CPU definitely has
> virtualization support
> - Networking is even more magic than in VMware and I couldn't figure
> out how to put the VM on NAT, it was always bridged to eth0.
> 
> Qemu
> + Open Source
> + Standalone solution that runs everywhere
> + Networking is clearly designed - it uses eth bridges in a non-magic
way
> + VNC support for console is a great idea
> + Can be managed from command line on the server
> - Terribly slow
> - By far the least user friendly from VMware and Xen for an average
user
> 
> KVM (+ Qemu)
> * I don't understand exactly what it does. Looks "just" like a
> speed-booster for Qemu to me and most of the userspace things come
> from Qemu. Is it something like a free implementation of kqemu module?
> + Speeds up Qemu to near-native speed.
> - Seems to be in heavy development that makes the userspace changing
> often (e.g. configuring the recent KVM according to howto written in
> november last year didn't quite work).
> Other +/- see Qemu
> 
> So far I'm undecided - all of these work nicely with Linux guests and
> that's what I need. I haven't done any benchmarks and all of them look
> reasonably comparable in speed.
> 
> Is there anything special and noteworthy about any of these
> technologies? Do you have any good stories and bad stories to support
> one one of them?
> 
> PaPa

I have to agree with Daniel about the fact that you're discussing
different technologies and comparing them. 

However, for what it's worth, here's my 2 cents.

I have tested several Virtualisation programs, and it would appear to
me, without a doubt at all, that VMWare is the most mature of them all.

What do I mean about mature? Vmware is stable enough for us (here at
work) to use in a production environment, with Windows and Linux servers
hosted under it, running live, serving virtual terminals, web pages,
etc... no problems. I cannot say this about any other Virtualisation
software, they pale in comparison in terms of reliability and speed.
(which is fair enough, most of them are younger than Vmware, and need
more development time).

HTH
Cheers,
Mike