[CentOS] Virtualization platform choice

Sun Mar 27 13:37:36 UTC 2011
Nico Kadel-Garcia <nkadel at gmail.com>

On Sun, Mar 27, 2011 at 8:53 AM, Drew <drew.kay at gmail.com> wrote:
>> Any experience with the free "VMware vSphere Hypervisor"?. (It was
>> formerly known as "VMware ESXi Single Server" or "free ESXi".)
>>
>> http://www.vmware.com/products/vsphere-hypervisor/overview.html
>>
>> I would need a tutorial about that... For example, does that run without
>> a host OS? Can it be managed only via Win clients? Issues with CentOS
>> 4/5 guests (all my systems are currently CentOS 4/5).
>
> vSphere ESX(i) is good product. It runs on bare metal so there is no
> OS underneath it. ESX has a linux based environment that sort of runs
> at the hypervisor level that people use for basic admin but VMware is
> trying to phase that out as most everything you can do with ESX's
> "console" can be done through ESXi's API's and the remote CLI.

I like vSphere in corporate environments, and LabManager with it for
burning guest images very quickly. The VMWareTools are not as
integrated as I would like, and their RPM names are quite misleading.
(The name of the file does not match the name of the actual RPM
reqported by `rpm -qf --%{name}-%{version}-%{release}.%{arch}.rpm\n',
and it's not as well integrated for kernel changes or host cloning as
I'd like. (Ask if you're curious.) But for corporate grade
virtualization, well built management tools, and corporate support,
they're very hard to beat. And for virtualizing weird old setups, like
SCO OpenServer 5.0.x, they're the only thing I tested that worked.

KVM was a dog in testing under CentOS and RHEL 5.x. The bridged
networking has *NO* network configuration tool that understands how to
set it up, you have to do it manually, and that's a deficit I've
submitted upstream as an RFE. It may work well with CentOS and RHEL 6,
i've not had a chance to test it.

VirtualBox is friendly, lightweight, and I'm using it right now under
MacOS X for a Debian box, and on Windows boxes for testing Linux
environments. Works quite well, friendly interfaces, very quick to
learn, I like it a light for one-off setups.

Xen, I did a stack of work with for CentOS 4 a few years ago. It
worked well, particularly with the para-virtualized kernels to improve
performance. (Don't virtualize things you don't have to!!! Uses custom
kernels to let the guest and server not waste time virtualizing IO
requests, especially for disk IO). I've not played with its management
tools since, and it didn't work well with virtualizing odd old OS's.
(I wanted to use it for OpenServer, but the "support team" who came
out to demonstrate it couldn't even get the keyboards interacting
reliably for the installation. It was a complete failure for that
project.)

You've got a lot of choices. I'd start with assessing what you need
for your guest environments, and where it's going to be managed from,
and be sure that you've got access to the management tools.

> Only downside to the free version is certain API's are unavailable and
> if you need those features you may have to go to a paid version.

This is true for everything in life.....