What is the difference between Virt and Cloud?

Why hybrid cloud and virtualization is different

That may not be a denial of hybrid cloud computing but it is not a strong endorsement either. You need to look for a company such as Red Hat for a strong statement about hybrid cloud and why virtualization is different.

"With virtualization, I am trying to take existing applications and servers and make them more efficient," says Bryan Che, general manager for the cloud business unit at Red Hat.

"You want to drive up the density, putting lots and lots of virtual machines on as few servers as possible, and still give yourself flexibility to deal with heterogeneous hardware.

“With cloud computing, I am trying to build for elasticity, to make my infrastructure scalable instead of trying to concentrate everything on one small rack of servers. It is about giving users fast access to something reasonably efficient."

Open to all

If anyone is banging the drum about hybrid, it is Red Hat. The company started the Deltacloud API stack to create a layer of transformation software that lets all the different public clouds and private cloud be controlled from a single console such as Red Hat's own CloudForms.

Red Hat understands the complexity of internal IT operations out there in the real world, according to Che.

"The public cloud providers have the luxury of being able to stamp out thousands or tens of thousands of servers at a time, all based on the same infrastructure and all running the same software," he says.

"They don't have to worry about legacy applications, they don't have a lot of heterogeneous infrastructure that they are managing.

"Enterprises, on the other hand, have been virtualizing their infrastructure and that has created a bunch of management challenges such as virtual machine sprawl.

“They have different virtualization clusters all over the place, running on different hardware, usually managed by different groups. They have multiple hypervisors.

"Developers are going into Amazon and other public clouds and they have no idea how to make it consistent or portable across those environments. And, the majority of their workloads are still running on physical systems."

The issue, as far as Red Hat sees it, is that it is hybrid capability that makes a cloud more than just server virtualization. It is not just an option but a requirement to meet the definition.

And by hybrid, Red Hat means something more sophisticated than building a private cloud based on a particular virtualization hypervisor and then finding a compatible public cloud to burst onto in short order if you need more compute capacity.

Cloud bursting is a niche case right now anyway, appropriate only for workloads with modest data sets and lots of compute (some high-performance applications are like this.)

Not everyone will agree on that definition of hybrid cloud, of course. But it is something Red Hat strongly believes that companies need to consider – before they get too far into any one set of cloud technologies.

"No one is going out and instantly transforming their entire data centre into a cloud," concedes Che.

"They start with one particular environment, one set of workloads and so on. But the important thing is which approach did you take? If you started out with something that was fundamentally open, and then even if your initial deployment is only on top of VMware or a particular set of hardware, I am able to extend that cloud over new infrastructure and I don't create these silos all over again."

Climate change

That is why Red Hat has spent some time creating Deltacloud APIs and CloudForms cloud management tools. It is trying get customers to think beyond the one little cloud they are building today and see the wider weather pattern they are creating across their data centers and public cloud partners.

El Reg would add yet another twist to the cloud definition, albeit an idealised tweak that would be nice if it were true: you can't call it a cloud unless you can get off it.

Perhaps Sir Mick would agree. But the hybrid nature that Red Hat is espousing (and that VMware believes will be only for special cases that account for maybe 20 per cent of the workloads on x86 servers, as Linux does today) is certainly not something other vendors talk about much.

They admit there is a slew of different equipment, operating systems, hypervisors and public cloud capacity being used. But they are not working together to allow application and data portability across corporate data centres, between data centres and public clouds, and across public clouds in a way that would give IT shops true flexibility.

Perhaps the problem is too tough and vendors just want to call something a cloud to get it past the bean counters.

We will get to a fully virtualized, automated data center eventually, and by that time we probably won't call it cloud any more. We will just call it computing. Or, perhaps more hilariously, processing.

In the meantime, the distinctions between well-established server virtualization and evolving cloud computing will be important. ®