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We've heard a lot of talk about the private cloud over the past decade, but do we really know what it is?
You know a public cloud when you see one: It's storage and services owned and run by the likes of Amazon, Google and Microsoft. In the 10 years or so since the public cloud has become a viable option for IT organizations, many attempts have been made to build private clouds on premises. But while public clouds are similar at their core, almost all private clouds are different. That makes it hard to identify -- let alone manage -- a true private cloud inside your data center.
IT vendors have tried to persuade customers they can sell them cloud building blocks to implement on premises, and vendors say they can even manage them for customers. But what were they selling? Lots of virtualization and multi-tenancy, but other public cloud features, such as elasticity and buy-as-you-go pricing, have been largely missing. What had been billed as private clouds weren't true private clouds; they were mostly traditional data center infrastructure.
The private cloud landscape is rapidly evolving, though. With the rise of building blocks such as hyper-converged infrastructure and mature software-defined storage, true private storage clouds are possible. They still can be hard to pinpoint accurately, but we're close enough.
A private cloud defined
Analyst firms are taking a good crack at defining private clouds. Wikibon's report on "2018 True Private Cloud Forecast and Market Shares" defined exactly what that should look like. The private cloud was also the theme of an IDC analyst presentation at VMworld in August. IDC analysts laid out the steps for building, orchestrating and managing a true private cloud, including a description of how it is different from what we've been calling private cloud.
"We've been talking about cloud for at least eight years, and it was public cloud and private cloud," said Stu Miniman, a Wikibon research analyst and one of the "True Private Cloud" report authors. "And what people were saying about the private cloud, it was BS. What I mean by that is, it was virtualization and yeah, we'll throw in a little orchestration and do a couple of other things, but it was virtualization-plus-plus. That's not a cloud."
Wikibon defined a true private cloud as one that has a single point of purchase, support, maintenance and upgrades. These characteristics describe hyper-converged infrastructure, but also services such as Hewlett Packard Enterprise GreenLake, Oracle Cloud at Customer and VMware Cloud Foundation.
Wikibon also pointed out architectures that aren't true private clouds. They include converged systems that aren't fully automated and orchestrated, heavily virtualized infrastructures that involve multiple vendors, including virtual private clouds such as Amazon Virtual Private Cloud and Azure Virtual Network.
Changing the conversation
IDC analyst Rick Villars said "We have to change the conversation" about private clouds. True private clouds are about having common clouds on dedicated systems more than everyone having their own cloud. Vendors that want to provide private clouds must offer easy connectivity and establish a software-as-a-service portfolio, he said.
"The problem with today's private clouds is every one is unique," Villars said. "There's no consistency in the environment. They're like old houses. The stairs are in different places; the plumbing's in different places; the wiring's all different. This is really hard to manage."
He said the road to consistency is to build clouds on a common foundation, which must be software-defined.
"In new private clouds, everything has to be consistent," Villars said. "It's about repeatability -- that I build the same thing again, again, again. When I go from one site to another, one data center to another, it's the same environment; it's the same model; it's the same structure. So we have to build it on software-defined foundation."
That makes hyper-converged a good fit for the true private cloud, but there is more to it than that. Wikibon laid out the characteristics of a true private cloud as the following:
- a simplified relationship between a user and a single provider either through a hyper-converged infrastructure or a hosted managed private cloud;
- available as self-service;
- flexible consumption models, either through pay-as-you-go pricing or long-term commitment; and
- the ability to work as part of a hybrid cloud.
Keep these features in mind when you set out to build your private cloud storage.
- Cloud Object Storage in Your Private Data Center –IBM
- Private Storage as a Service at the Edge –Equinix
- Focus: Private cloud –ComputerWeekly.com
- High-performance Private Cloud Toolbox –IBM