to says they’ll have at least three.
mache cReeGeR: As a large enterprise
customer, aren’t you worried about
having isolated islands of function-
ality?
GustaV: No, I have HP and Dell.
That’s a desirable case.
mache cReeGeR: But that’s different.
They have the x86 platform; it’s rela-
tively standardized.
simon cRosBY: It’s not. You’ll never
move a VM between AMD and Intel—
not unless you’re foolhardy. They have
different floating point resolution and
a whole bunch of other architectural
differences.
People tend to buy a set of serv-
ers for a particular workload, virtual-
ize the lot, and run that workload on
those newly virtualized machines. If
we treated all platforms as generic,
things would break. AMD and Intel
cannot afford to allow themselves to
become undifferentiated commodi-
ties, and moreover, they have a legiti-
mate need to innovate below the “vir-
tual hardware line.”
mache cReeGeR: So you are saying
that I’m going to spec a data center for
a specific workload—spec it at peak,
which is expensive—and keep all
those assets in place specifically for
that load. Doesn’t that fly in the face
of the discussions about minimizing
capital costs, flexibility, workload mi-
gration, and high-asset utilization?
tom BishoP: You’re making an as-
sumption that every business defines
risk in the same way. Gustav defines
risk in a particular way that says “The
cost of excess capacity is minuscule
compared to the risk of not having the
service at the right time.”
mache cReeGeR: In financial services,
that’s true, but there are other people
that can’t support that kind of value
proposition for their assets.

simon cRosBY: That’s an availability argument, where the trade-off is between having the service highly available on one end of the line, and lower capital costs, higher asset utilization, and lower availability at the other end. Virtualization can enhance availability.

GustaV: You will tend to use the VM, because while there are differences now at the hypervisor level, those differences are converging relatively rapidly and will ultimately disappear.

If you’re worried about the long-

aLLen ste WaRt
the thing that
challenges the
cloud environment
and most enterprise
data centers is the
heterogeneity of the
shop and the types
of applications
they run. to take
advantage of
the cloud, you
have to develop
to an application
model that suits
disconnected state
and applications.

term trend of hypervisors, you’re worried about the wrong thing. Choose the VM that is most compatible today to the application you are going to run. If you’re doing desktop virtualization, you’re probably going to use CXD (Citrix Xen Desktop). If you’re doing Windows server virtualization, you’re going to use either Veridian or, depending on what you’re trying to do regarding availability management, VMware.

The first question to ask is “What are you used to?” That’s going to determine what you’re likely VM is. The second question is “What is the problem you’re trying to solve?” The more complex the management problem the more attractive an integrated tool suite from VMware becomes. If you are saying “I don’t have complex problems now but I’m going to have complex problems in three or four years,” the more attractive Microsoft becomes. If you are going to build it on your own and/or have your own toolsets to integrate, which is most of the enterprise, you’re going to find the Xen/Citrix option more attractive. If you’re coming from the desktop side, you’re at the other side of Citrix, and that is back to Xen. Where you’re coming from is going to determine your VM product selection much more than where you’re going to because they’re all heading to the same place.

simon cRosBY: Looking at Microsoft Hyper-V/System Center and VMware VSX and Virtual Center (VC), both of these are complete architectures. Neither of them has a well-established ISV ecosystem significantly limiting customer choices. That said, I think the ecosystem around VMware is now starting to emerge due to the adoption of standards-based APIs.

What worries me is whether the missing functionality in any vendor’s product needs to be developed by the vendor or whether the customer is OK with a solution composed of a vendor product and ISV add-ons. Both Stratus and Marathon offer fault-tolerant virtual machine infrastructure products using Citrix XenServer as an embedded component. That’s because they focus on how to build the world’s best fault tolerance whereas Citrix, VMware, and Microsoft do not. We have an open architecture, and that allows