Virtualization

[Christopher A. Williams]

On Tue, 2011-08-02 at 17:43 -0400, Jorge Fábregas wrote: 
> On 08/02/2011 04:50 PM, Christopher A. Williams wrote:
> > I specialize in virtualizing Oracle Databases (among other things).
> > Given the choices of virtualization platforms you gave, I would tend to
> > go with either VirtualBox or KVM, in that order of preference.
> 
> Hi Christopher,
> 
> To this day, as far as I know, Oracle doesn't certify their database on
> any virtualization platform other than theirs.  That said,  I know many
> people run Oracle over VMware and I also haven't heard any stories of
> Oracle not wanting to support a customer because they were running a
> non-certified virtualization platform.  However, I still think the OP
> needs to be aware of this just in case.

This is misleading at best and untrue from a practical matter. The key
is support as opposed to certification, and Oracle DOES support their
database systems on VMware. There is an official support statement from
Oracle to that effect.

The reality is that Oracle only *certifies* to the Operating system
layer, and VMware vSphere (ESX/ESXi) is considered hardware in that
regard. Ask Oracle if they certify their database on IBM vs. HP vs. Dell
hardware and you'll find that they don't certify any of them.

> 
> > However, if I may, you will be much better off handling these things
> > from a performance point of view using a bare metal hypervisor, and in
> > that case, I would recommend the free version of ESXi. 
> 
> I think KVM is considered a bare metal hypervisor as well.  I haven't
> used it  but I was wondering if you had performed any tests (performance
> wise) on Oracle over KVM vs Oracle over ESXi?

KVM is considered a bare metal hypervisor by mainly the KVM folks. It
actually bolts a hypervisor straight into the Linux kernel. It's clearly
a better situation than a Type 2 hypervisor (and one I happen to like a
lot), but you could question if it really is a full, pure bare metal
class of the likes of ESX/ESXi and even OVM for that matter.

I haven't done any explicit performance testing pitting KVM against
ESX/ESXi yet and will hold off on doing any until vSphere 5.0 hits the
streets as well. That's because there are significant performance
increases in vSphere 5.0 (they have announced an increase from 300,000
IOPS to 1,000,000 IOPS for example). I can tell you that I have
configured and tuned VMs on ESXi 4.1 which have performed as fast as
their physical counterparts, sometimes even a little faster running
Oracle, SQL Server, DB2, and Sybase.

As an aside, it's also a little misleading to question certification
with respect to VMware but not KVM, which is neither certified (for what
that's worth) nor explicitly supported in the way that VMware is -
particularly when it comes to RAC versions 11.2.0.2 and later.

Cheers,

Chris

-- 

======================
"Only two things are infinite,
the universe and human stupidity,
and I'm not sure about the former."

-- Albert Einstein