That's a funny looking cow, I mean chicken, I mean cow

By Aaron Sweemer
published: Thursday, November 06 2008

I've got a super corny joke for you.  What do you get when you cross a brown chicken with a brown cow?  Give up?  The answer is ... Brown chicka brown cooooooooooow!  Hehehehe.  That joke makes me giggle every time.  (If you don't get it, say it out loud.  If you still don't get it ... um, wow).  And recently, when I hear someone preaching about diversifying virtualization vendors, this joke comes to mind.  I suppose this is because I believe building a virtual infrastructure by mixing and matching virtualization vendors is like trying to cross breed two species that should never be crossed.  Attempting to do so might be fun for the sick and twisted mad scientist (or IT administrator, as the case may be).  But even a successful attempt would result in something unholy at worst and at best, the laughing stock of the barnyard.

Yes, yes, I know.  The multi-vendor evangelists are convulsing on the floor right now, spewing obscenities and foaming at the mouth.  My humor isn't often well received by those on the other side of the fence.  So I suppose this is a good time to clarify a few things.  And I need to clarify before the convulsing progresses into a full-on conniption fit that would have Dr. Phil in tears, reaching for the bourbon and speed dialing his B.F.F. (Oprah) for a good old fashioned pep talk.

First, I'm NOT saying that you shouldn't do your homework and evaluate your virtualization vendor options in a controlled lab environment.  And if you're evaluating virtualization vendors, then of course you'll have a mixed lab environment.  And second, I'm NOT saying that you need to pick a single vendor for every virtualization genre that exists (server, desktop, application, etc).  What I am saying, however, is that you are asking for big trouble if you start to mix and match vendors within a given type of virtualization.  Now the multi-vendor proponents often use one of two main arguments against this statement.

The First Argument

What if someone figured out how to crack the VMware hypervisor?  If VMware is your only vendor then your entire infrastructure would be at risk, whereas in a multi-vendor environment, only a portion of your infrastructure would be at risk.  And possibly you could move your workloads over to the other vendor's virtual infrastructure until the security flaw is patched.

Why I Disagree

While there exceptions to every rule, most IT departments have standardized on a particular Operating System.  And with good reason, standardization is the key to stable, predictable and manageable environments.  And are they susceptible to infrastructure wide outages?  Heck yeah they are!  As an example, I'm sure everyone's heard of "Patch Tuesday" (the second Tuesday of the month when Microsoft releases its security patches)?  Skype experienced a two-day outage last year because their OS vendor, Microsoft, introduced instability via the automated Patch Tuesday updates.  And right now you might be laughing thinking that I've just confirmed the need for multiple vendors.  But really what I'm trying to point out here is that this risk is going to exist when you have a single vendor at any layer (hardware, virtualization, OS, application), not just the virtual layer.  More importantly, with proper security and patching measures in place, this risk can be mitigated and possibly even eliminated.  The Skype outage could've been avoided.  And at the end of the day, there are much greater risks and costs to worry about when you've got two or more vendors at the same layer.

I believe standardizing on a single vendor is the way to go, and I've got a great example for you to help make my case.  Southwest Airlines has been the golden child of the aviation industry and almost the definition of what a successful airline should look like.  And it's no wonder they have an impeccable safety record and 35 straight profitable years in an extremely turbulent industry (no pun intended).  Do you know what they attribute as a major key to their success?  Streamlining operations through standardization.  And do you know how many different types of aircraft they fly?  One, the Boeing 737.  Yes, I know they fly three different versions of the 737, but it's all 737 and it's all Boeing.  This gives them a tremendous advantage in a couple areas.  Training is streamlined as pilots, flight attendants and mechanics need to know one type of aircraft, and they know it well.  Parts inventory can be kept much lower and inventory tracking is far less complicated.  Scheduling is much more efficient because every pilot and flight attendant can fly any plane.  And their strategic relationship with Boeing affords them opportunities unavailable to other carriers, such as better pricing and collaborative efforts between engineering teams.