have a VM and to put the policy around that VM for late binding is pretty powerful. You create your application or your service, which might be a multi-machine service, and you associate with it the security level you want, the availability level you want, and the SLAs (service level agreements) that should go with it. The beauty of this bubble, which is the workload and the policy, is it can move from one data center to another, or to an offsite third party, if it satisfies the demands that you’ve wrapped around it.

GustaV: Our administrative costs generally scale in a nonlinear fashion, but the work produced is based on the number of operating-system instances more than the number of hardware instances. The number of servers may drive some capital costs, but it doesn’t drive my support costs.

tom BishoP: What you’re really managing is state. The more places you have state in its different forms, the more complex your environment is and the more complex and more expensive it is to manage.

simon cRosBY: I’ll disagree. You’re managing bindings. The more bindings that are static, the worse it is, the more they are dynamic, the better it is.

We have a large financial services customer that has 250,000 PCs that need to be replaced. They want to do it using VDI (virtual desktop infrastructure) running desktop OSes as VMs in the data center to provide a rich, remote desktop to an appliance platform.

Following the “state” argument, we would have ended up with 250,000 VMs consuming a lot of storage. By focusing on bindings, given that they only support Windows XP or Vista, we really need only two VM images for the base OS. Dynamically streaming in the applications once the user has logged in allows us to provide the user with a customized desktop, but leaves us with only two golden-image VM templates to manage through the patch-update cycle.

Steve Herrod, Mike Neil from Microsoft, and I have been working on an emerging standard called OVF to define a common abstraction to package applications into a container. Under this definition, an application is some number of template VMs, plus all the

steVe heRRoD
the opportunity
to have a Vm and
to put the policy
around that Vm
for late binding is
pretty powerful.
You create your
application or
your service. the
beauty of this
bubble, which is
the workload and
the policy, is it can
move from one data
center to another,
or to an offsite third
party, if it satisfies
the demands that
you’ve wrapped
around it.

metadata about how much resource they need, how they’re interconnected, and how they should be instantiated.

We started working on it because there was the potential for a “VHS versus Betamax” virtual-hard-disk format war and none of us wanted that to happen. It started out as a portable virtual-machine format but is now emerging into more of an application description language. The container contains one instance of every component of the application, but when you roll it out at runtime you may request multiple copies. I think that’s a very important step forward in terms of standardization.

steVe heRRoD: Virtualization breaks up something that’s been unnaturally tied together. However, allowing late binding introduces new problems. If you cannot be more efficient with virtualization, then you shouldn’t be using it.

We do surveys every single year on the number of workloads per administrator. Our numbers are generally good but it is because we effectively treat a server like a document and apply well-known document-management procedures to gain efficiencies. This approach forces you to put processes around things that did not have them before. For smaller companies that don’t have provisioning infrastructure in place, it allows you much better management control. It’s not a substitute for the planning part, but rather a tool that lets you wrap these procedures in a better way.

mache cReeGeR: So how do people decide whether to choose VMware, Citrix, or Microsoft? How are people going to architect data centers with all the varying choices? Given that the vendors are just starting to talk about standards and that no agreements on benchmarking exist, on what basis are people expected to make architectural commitments?

GustaV: I think this is a place where the technology is ready enough for operations, but there are enough different management/software theories out there that I fully expect to have VMware, Microsoft, and Xen in different forms in my environment. That doesn’t concern me nearly as much as having both SuSE and RedHat in my environment.

tom BishoP: Every customer we talk