Q&A: Building a Private Cloud
We examine the benefits and uses of building a private cloud, and explain the implementation best practices.
"In the cloud" has become a popular phrase lately. Which type of cloud is right for your enterprise? What are the benefits and distinctions between public and private clouds? To shed light on the subject, we spoke with Sheng Liang, CEO and founder of VMOps. We explore the benefits, uses, pitfalls, and technical challenges of developing your own private cloud. Mr. Liang's firm (http://www.vmops.com) develops software for creating and managing elastic private computing clouds.
Enterprise Strategies: IT has shown strong interest in cloud computing recently. How do you define an enterprise cloud?
Sheng Liang: There was initially a lot of confusion about the definition of a cloud, but over the past year, vendors, industry analysts, and the press have done a great job clarifying the concept of cloud computing. There is now general agreement that cloud computing represents a shift towards delivering dynamically scalable IT resources as services over the Internet. These services typically share some key attributes, such as elasticity, resource sharing, multi-tenancy, self-service, and pay per use. Three types of services can be delivered via cloud computing: infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS).
What's the difference between a public and private cloud? What are the advantages of each, and why should an enterprise consider deploying a private cloud?
The main differences between a public and private cloud are where it resides and if it is dedicated to a single company. If an enterprise decides to host cloud services in their own data center, that is considered a private cloud; if they use cloud services hosted by service providers, it is probably a public cloud.
In the case of an infrastructure cloud, a good example of a public cloud of this kind is Amazon EC2, where users can create accounts and immediately deploy virtual machines on shared infrastructure. This same type of service can be deployed inside the firewall as a private cloud.
There are definitely shades of grey here. For example, some service providers are hosting dedicated infrastructure clouds for clients. In this case, a company’s infrastructure cloud doesn’t reside in its data center but it is isolated from other users. This is often called a virtual private cloud.
Depending on whether you are deploying a cloud for IaaS, SaaS, or PaaS, there are different issues to consider when you compare private clouds and public clouds.
- For SaaS, the general consensus is that enterprises should develop applications that give them a unique competitive advantage in house and leverage public clouds for general-purpose utility applications.
- PaaS is the least mature type of public cloud. Right now, public PaaS clouds are mostly targeting Web developers. There aren’t many examples of enterprise private deployments of PaaS. Lack of a standard dominant enterprise application development platform is the biggest reason you don’t really see PaaS in the enterprise.
- Infrastructure clouds are the fastest growing segment among the three delivery models. Enterprises get clear benefits by using public IaaS cloud or building a private IaaS cloud. The IaaS model has been so successful that several variations have emerged: Virtual private cloud is a public cloud offered by service providers that it is built on isolated, highly-secure, or dedicated resources for each customer. Another variant, the Hybrid cloud, enables enterprises to run workloads on premise and migrate to public clouds when needed.
What are some of the common uses of a private infrastructure cloud?
At its core, an infrastructure cloud enables enterprises to manage computing resources more efficiently. Let me give you some examples of how people are using infrastructure clouds today.
- Some companies are leveraging the self-service and automated provisioning features of a private cloud to make it much easier for developers, researchers, IT, and even business units to get access to computing resources. With an infrastructure cloud, a researcher can request and have provisioned a private network with dedicated storage and five VMs in less than 10 minutes.
- Because infrastructure clouds track utilization and allow users to elastically add and destroy resources as needed, companies are using private clouds to easily account for resource consumption at a project or department level, simplify chargeback, and reclaim resources that are no longer in use.
- Infrastructure clouds also are very effective a managing large workloads and scheduling resources so that companies can utilize computing, storage, and networking resources more efficiently.
- Finally, the automation and configuration management built into an infrastructure cloud makes it possible for companies to reduce the need to manually administer their computing infrastructure.
How does a private cloud work with existing infrastructure, applications, and IT processes?
A private infrastructure cloud is deployed on physical infrastructure that includes computing servers, storage, and networking. The cloud incorporates virtualization and management technologies that abstract away the physical infrastructure and present to the application layer virtual computing servers, virtual storage, and virtual networking.
The advantage of a private infrastructure cloud is that applications do not know they are running on virtual infrastructure as opposed to physical infrastructure. Because of this, you don’t need to change applications or IT process that have been developed to work in a physical data center.
Can enterprises mix and match public and private cloud offers? For example, can they leverage public cloud offerings from service providers to enhance their private cloud offering?
Yes, absolutely. The hybrid cloud use case includes cloud bursting where enterprise workloads can migrate between private and public clouds. There are almost as many different approaches to this as there are service providers. One very popular approach is a virtual private cloud, where a company might have a dedicated rack or two of servers in a service provider’s data center; the racks are connected to a private cloud the enterprise has running on its premises.
What are the security implications of a cloud? Are there special implications for a private cloud?
This is a really big and commonly asked question about cloud computing. Security, isolation, and multi-tenancy are key requirements of any cloud. Even though multi-tenancy is built into every public cloud, it will take some time before enterprises are comfortable trusting cloud provider security and placing sensitive corporate data on the public cloud. In the short term, therefore, I think you’ll see that most companies will leverage private clouds for applications and projects that are sensitive or have compliance requirements.
What are the pitfalls an enterprise may experience when they embark on a private cloud strategy? What best practices can you suggest to avoid such problems?
One thing I hear a lot from large companies is that they are concerned about building a private cloud and being locked into a specific vendor’s technology. Not surprisingly, the largest technology companies are seeing the move toward public clouds as a chance to sell massive “transformational” solutions to their customers. These solutions, however, typically lock a customer into some type of hardware, storage, or hypervisor. Companies considering deploying a private cloud should really focus on ensuring their cloud can support lots of different types of storage, hardware, and even different hypervisors.
At a higher level, just like any other major technology shift, enterprises may run the risk of moving too early and end up making investments that do not translate to return, or they may run the risk of moving too late and end up losing to competitors. The key is to start early with small-scale deployments and gain experience before adopting an enterprise-wide cloud strategy.
How can an enterprise get started to deploy a private cloud?
Actually, setting up a small cloud isn’t that hard. Most companies simply identify one of several common use cases and create a small-scale deployment. A good example might be a rack or two of servers dedicated to the software development or research departments. This will bring immediate benefit to the business while helping the enterprise evaluate and plan a long-term cloud strategy.
What are some of the technical challenges in building and deploying a private cloud?
Building an infrastructure cloud poses a great number of technical challenges. A cloud relies on sophisticated software to abstract away physical servers, storage, and networking infrastructure. The software must therefore include the hypervisor, storage management, and network management. It should also offer strong security and isolation guarantees to support multi-tenancy and scale to meet the requirements of the enterprises including number of servers, geographically distributed data centers, etc. Finally, the software must offer advanced management features to support self service, work load, and configuration management, and chargeback.
What role does VMOps play in the private cloud market?
VMOps has created a turnkey software stack that enables enterprises to easily build and manage infrastructure clouds. The VMOps Cloud Stack consists of the management server and multi-tenant hypervisor. The management server provides a self-service UI and API, workload and configuration management, and chargeback. The multi-tenant hypervisor incorporates storage and network management using industry-standard hypervisors. The VMOps Cloud Stack can scale to thousands of servers in multiple data centers and can bridge an enterprise’s private cloud with public cloud services such as Amazon EC2.
Sheng Liang is CEO and founder of VMOps, a provider of software that enables enterprises and service providers to create and manage elastic private computing clouds. Mr. Liang is a technology visionary who developed the Java Virtual Machine at Sun Microsystems, and a serial entrepreneur. He co-founded Web application firewall vendor Teros Networks (acquired by Citrix), and was a member of the senior management team at SEVEN Networks and Openwave Systems, which developed software products for over 100 wireless and wire-line service providers around the world. You can reach Mr. Liang at firstname.lastname@example.org.