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Evaluating OpenStack vs. VMware for private cloud

OpenStack and VMware are both viable options for hybrid and private cloud. So which one should your organization choose?

Different vendors hold different views about the future of cloud computing. Amazon Web Services, for example, believes private and hybrid clouds are only a stepping stone on the road to public cloud. But enterprise concerns around job protection, security and compliance are leading to private and, especially, hybrid cloud deployments. According to industry analyst IDC, more than 65% of enterprise IT organizations will commit to the hybrid cloud model before 2016.

But when it comes to hybrid cloud implementation, things can be less organized than some would hope. In hybrid clouds, data is transferred between public and private clouds, but the parlous state of WAN communications, especially in the U.S., makes this a problem.

Another issue with hybrid cloud implementation is choosing the right private cloud technology. Many companies use OpenStack as the core private cloud software within a hybrid environment. OpenStack sits on top of a hypervisor and consists of a complex suite of modules that provision and orchestrate the cloud. It's an open source project and most of the industry's heavy hitters, including HP, Dell, IBM and Google, are deeply involved.

VMware and OpenStack integration challenges

Many VMware users have wondered how to use their current virtual server pool to create a private cloud that can communicate with a public cloud. With large investments in VMware training, licenses and processes, some organizations view any private cloud alternative to VMware as daunting. But when it comes to hybrid cloud design, a lack of clarity from VMware made life difficult.

Running OpenStack on VMware virtualized servers isn't the issue -- but we have to be careful what part of VMware we are talking about. Here, we are referring to the ESXi hypervisor. There are overlaps and interface issues with higher-level VMware technology, including vSphere and vCenter, which certain OpenStack functions match.

Another integration issue is connecting VMware vSphere-controlled local storage with OpenStack's Swift object store. Because it's block IO-oriented, VMware doesn't have a direct equivalent to Swift.

OpenStack vs. VMware in the private cloud arena

OpenStack began as cloud technology, while VMware started as a virtualization suite for the data center. Since they belong to two different generations of architecture, a direct comparison of OpenStack and VMware is difficult. Some OpenStack services align with VMware's, but it's a short list. Out of the 30+ modules accepted for the OpenStack project list, only four -- Nova for compute, Glance for image management, Neutron for networking and the Horizon dashboard module -- bear direct comparison to VMware.

VMware's vCloud strategy makes it difficult to compare the two technologies. While vCloud competes with OpenStack, it lacks the scope of features that OpenStack displays. To many, this reflects VMware's late acceptance of the cloud as an enterprise reality, and puts the company in a catch-up position.

Cost further fuels the OpenStack vs. VMware private cloud debate. The VMware ESXi hypervisor is free, but the rest of the code requires consumers to pay licensing fees. Facing a rapid expansion of server farms over the next decade, many CIOs are exploring lower-cost options -- and that rationale is driving many organizations to OpenStack. While OpenStack can introduce higher support costs, that's also true of VMware. Ultimately, though, it's generally less expensive to go down the OpenStack path.

Meanwhile, some larger companies have their eye on "whitebox" commodity hardware to reduce costs. For those organizations, OpenStack may be the better option, since VMware has its own list of approved hardware configurations.

There are other considerations in play.

OpenStack is just three years old and still evolving. The core is stable, but it hasn't matured enough to match VMware's quality standards. Many newer OpenStack features are still in early development, but it's here that the modular OpenStack approach shines. OpenStack is more like a cloud "Lego," meaning new pieces and modules will be added over time -- likely even 30 years from now.

VMware vCloud is also new and, in many ways, less mature than other technologies. VMware needs a lot of features to catch up to OpenStack. The company partners with AT&T and Terremark to offer hybrid cloud capabilities, but some believe VMware faces a steep learning curve because it arrived late to the market. vCloud also uses internal hypervisor installations with VMware public cloud capabilities, meaning a truly open, provider-agnostic VMware option is a long way into the future.

VMware recently launched its own OpenStack distribution. VMware Integrated OpenStack -- software that supports OpenStack in vCenter and vSphere environments -- became available in March. While it's too early to determine the effectiveness of this approach, it introduces an extra layer of indirectness that may affect performance. It's also more complex and keeps those expensive licenses in place.

OpenStack is finding its place in the enterprise, even among organizations that have drunk the VMware Kool-Aid for years. Many companies have gotten their feet wet with OpenStack, and it's no longer valid to just assume VMware is the better option.

About the author:
Jim O'Reilly was Vice President of Engineering at Germane Systems, where he created ruggedized servers and storage for the US submarine fleet. He has also held senior management positions at SGI/Rackable and Verari; was CEO at startups Scalant and CDS; headed operations at PC Brand and Metalithic; and led major divisions of Memorex-Telex and NCR, where his team developed the first SCSI ASIC, now in the Smithsonian. O'Reilly is currently a consultant focused on storage and cloud computing.

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