In the early days of cloud computing, private clouds promised the scalability, elasticity, and manageability of public clouds combined with the security and control over on-premises data center environments.
For many years, however, it seemed this promise was unjustified, as vendor ‘cloudwashing’ obscured the sad fact that rather than being the best of both worlds, private clouds were actually the worst.
Early private clouds, in fact, were neither private nor clouds. Many such clouds either ran in public cloud environments (thus undeserving of the appellation ‘private’) or suffered from a lack of any cloud benefits.
Today, however, private clouds have taken a prime position in the pantheon of hybrid IT – a mix of public and private clouds as well as on-premises virtualized and legacy environments.
Do today’s private clouds finally warrant some respect? Or are they simply vendor cloudwashing 2.0?
Early Private Clouds Fall Short
The National Institute of Standards and Technology (NIST), an agency of the US Department of Commerce , formulated the core definitions of cloud computing back in 2011, including the definition of private cloud. “Private cloud: the cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple consumers (e.g., business units),” according to The NIST Definition of Cloud Computing by Peter Mell, senior computer scientist and Timothy Grance, manager of systems and network security. “It may be owned, managed, and operated by the organization, a third party, or some combination of them, and it may exist on or off premises.”
Private clouds, therefore, might be on or off-premises – but in the early days, the goal was generally on-premises, in order to bring the benefits of public clouds to the corporate data center.
Many vendors jumped into this market, putting together various ‘cloud in a box’ offerings that purported to meet the requirements for private cloud, with limited success. The problem? Getting cloud right turned out to be harder than everyone thought, and such early private clouds didn’t offer the scalability, elasticity, and resilience that were the most important characteristics of the cloud.
Over time, however, such offerings matured. “Private cloud leverages the benefits of public cloud, including rapid deployment, scalability, ease of use and elasticity,” touts the recent IBM IBM -0.24% Cloud white paper How to get the benefits of cloud behind your firewall: IBM Cloud Private, “but can also offer additional capabilities such as greater control, increased performance, predictable cost, tighter security and flexible management options.”
For the most part, however, while vendors fell short, the public cloud providers stepped into the private cloud game. An early offering: virtual private clouds (VPCs). “Virtual private cloud is an on-demand configurable pool of shared computing resources allocated within a public cloud environment,” explains the Global Virtual Private Cloud Market 2018 by Manufacturers, Countries, Type and Application, Forecast to 2023 by Market Research Vision (purchase required). “It provides a certain level of isolation between different organizations using the resources.”
VPCs, therefore, offered the cloud characteristics that enterprises craved, but were only ‘private’ in the sense that their network settings were logically behind the corporate firewall – although physically, VPC resources shared data centers, racks, or possibly even servers with third-party cloud resources outside the private cloud.
Reconsidering the Private Cloud
In addition to the various ‘cloud in a box’ vendor offerings, an open source effort also sought to fill the private cloud void: OpenStack. However, as I warned in an article back in 2015, OpenStack proved overly complex and poorly managed to address most enterprise private cloud use cases.
Today, OpenStack is on the wane. “Private cloud operating systems, such as OpenStack, are falling out of favor with enterprises,” explains David Linthicum, chief cloud strategy officer at Deloitte Consulting, in his Remove Hybrid & Multi-Cloud Complexity and Take It to the Next Level: A GigaOm Market Landscape Report (purchase required). “Hybrid clouds are moving away from paired public and private clouds, to paired public and legacy systems.”
Hybrid clouds – which NIST originally defined as a mix of public and private clouds – were now dropping the private cloud portion of this equation altogether.
A Dell DELL +NaN% EMC executive in China concurs with Linthicum’s take. “Enterprises are returning to adopt solutions provided by major software developer such as VMware VMW -0.37% or Microsoft MSFT -1.59%,” explains Felix Xu, director of Dell EMC Greater China’s cloud business. “Many of them originally hoped to avoid the control of these large solution providers by using open source software such as OpenStack, but it has turned out such open source platforms do not have resources necessary for further development of these platforms to meet their needs.”
The VMware and Microsoft solutions Xu is referring to, however, are unlikely to be private clouds – or at least, not first-generation private clouds. VMware, for example, has been extending its virtualization environments to public clouds, while Microsoft is a public cloud provider that is offering an on-premises version of Azure.
The Hybrid IT Future of Private Cloud
Today, while private clouds still retain their identity as a separate offering, they are more likely to be one part of a broader hybrid IT strategy. “From a customer’s perspective, there’s a lot more options than there’s ever been to break down the divide between on premises and the public cloud,” explains Chadd Kenney, CTO and VP of product and solutions for Pure Storage.
Pure Storage is only one of several vendors who is capitalizing on this trend. “The private cloud vendors, including brands like Nutanix , Dell EMC, and Red Hat RHT +0.3%, continue to grow steadily and there are hardware-centric, software-oriented and hybrid offerings to meet every need,” says David McCall, VP of Innovation for QTS Data Centers.
One of the primary drivers of this hybrid IT strategy is the realization that public clouds don’t meet every enterprise need – and that a ‘cloud first’ or ‘cloud migration’ strategy need not be all about public cloud offerings. “When you look at large enterprises, there’s been almost zero movement to put their major systems of record into Amazon AMZN -5.52% or Azure or any other public cloud,” explains David Floyer, CTO and co-founder of Wikibon. “There’s a realization that it’s much better to create the cloud near where the data is processed than move it.”
Furthermore, while OpenStack fell short, Kubernetes and the rise of containers generally is also having a significant impact on the role private clouds play within enterprise hybrid IT strategies (see my December 2018 article on the rise of Kubernetes). “We’re going to see private clouds and even multi-clouds start to increase support for Kubernetes,” says Andy Walls, IBM fellow and CTO of IBM Flash Storage. “Many private clouds are increasingly based on containers. Therefore, Kubernetes support is going to increase and expand, and along with that, if that becomes the de facto standard, you can more easily go from one cloud vendor to another.”
In the final analysis, then, the question about the role of private clouds becomes part of the hybrid IT discussion – more an implementation option than a strategic decision in its own right. “It’s really more about the application and the outcome and transforming those things to take advantage of modern systems than a light-and-dark contest between public and private cloud,” explains Carl Brooks, IT analyst at The 451 Group. “Depending on the exact scenario, it could be cheaper to run [a workload] in private cloud versus public cloud [or vice versa], but it is very dependent on the workload and outcome.”
This workload centricity, in fact, is at the heart of hybrid IT, as workloads connect the infrastructure to the applications that IT puts in front of customers. Distinctions of public vs. private vs. hybrid eventually become implementation details that organizations can configure as a matter of policy, while supporting the changing needs of customers in the digital era.
Intellyx publishes the Agile Digital Transformation Roadmap poster, advises companies on their digital transformation initiatives, and helps vendors communicate their agility stories. As of the time of writing, Pure Storage is a current Intellyx customer, and IBM, Microsoft, and VMware are former Intellyx customers. None of the other organizations mentioned in this article are Intellyx customers. Image credit: Seeweb, Karen Roe, and Jason Bloomberg.