Despite all of the hype surrounding cloud storage these days, it remains a difficult concept to fully explain. It can get even harder to grasp when divided into subtypes of cloud storage, such as private and public clouds, internal cloud, external cloud and hybrid cloud, each still evolving and at times overlapping.
This series will shed light on cloud storage options, beginning with this introduction into the terms and goals driving the cloud concept. The subsequent parts of the series will include closer looks at external and internal storage clouds, followed by a peek at where cloud storage is heading.
Academic researchers seek to set boundaries
A lot of effort went into the process of coming up with formal definitions for the storage cloud last year. A research team from the University of California at Berkeley's Electrical Engineering and Computer Sciences department took a shot at it last February with a paper called "Above the Clouds: A Berkeley View of Cloud Computing."
According to the Berkeley researchers, "Cloud Computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the data centers that provide those services." Other key concepts include "the illusion of infinite computing resources available on demand … the elimination of an up-front commitment by cloud users … [and] the ability to pay for use of computing resources on a short-term basis as needed (e.g., processors by the hour and storage by the day) and release them as needed." The Berkeley researchers acknowledged, but excluded the concept of a private cloud from their report.
Many of these concepts now considered "cloud" have been around for years under different labels. A normalized view of an infrastructure could also be attributed to older concepts of service-oriented architecture (SOA). The prominent role played by service providers in cloud computing harkens back to a cycle of outsourcing boom-and-bust in the early 2000s. According to the Berkeley paper, "Cloud Computing is a new term for a long-held dream of computing as a utility."
The National Institute of Standards and Technology (NIST) Information Technology Laboratory released its own paper last June called the "Draft NIST Working Definition of Cloud Computing." According to NIST: "The cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on-premise or off-premise."
NIST breaks the cloud into subtypes, including public clouds, private clouds and hybrid clouds. NIST also identifies a category it calls "community cloud," a cloud infrastructure shared by multiple organizations or a community with shared concerns, which may be internally or externally deployed. Like University of California at Berkeley, NIST also identifies elasticity in resource deployment, user self-service, ubiquitous network access to resources and location-independent resource pooling as key elements of a cloud, whether deployed internally or externally.
Rent-a-cloud or a cloud of your own?
Of course, storage vendors all have their take on the cloud. EMC Corp. and VMware Inc., two of the most vocal vendor proponents of the cloud concept, see utility computing as the long-term goal. EMC and VMware maintain the move to utility computing will begin with internal virtual data centers, followed by hybrid infrastructures that straddle internal and external data centers. Emerging private cloud software vendor ParaScale Inc. joins EMC and VMware in describing the cloud as a continuum from virtualized storage-area networks (SANs) to the Amazon/Google model of Web–based storage applications.
"Ninety percent of people think about cloud as pay-as-you-go, on-demand public access to compute and storage resources," said ParaScale CEO Sajai Krishnan. "The public cloud will continue to evolve, but there will continue to be concerns, especially about performance."
Krishnan said the cloud fundamentally comes down to a virtualized, flexible architecture and refers to a general movement in IT to move intelligence into software.
"People are thinking of this today like a car you have to rent to drive," Krishnan said of the focus on service providers in defining cloud computing and cloud storage. "We're trying to get people to see they can also own the car."
Bob Wambach, EMC's senior director of storage product marketing, puts it another way. "You can build this within your four walls first and build trust," he said.
But how do users know whether a virtualized infrastructure counts as a "cloud" or not? "It's about what you spend your time doing – planning, monitoring or forecasting for the business, or do you spend time doing configuration and management changes?" Wambach said. "That tells you where you are on the journey."
EMC representatives said continuing data growth makes it mandatory to build more automation into virtual data center products—in a sense, abstracting the infrastructure even from IT administrators as well as end users within the organization. And they see this automation occurring whether or not enterprises embrace external service providers.
"The response time of an administrator is not fast enough to keep up with the dynamic change of a virtual environment," said Brian Gallagher, senior vice president and general manager of EMC's Symmetrix product group. "It's like fighter jets – pilots used to fly them, now the jets fly the pilots, and ultimately they have no pilots in them with things like the Predator drone."
EMC, VMware and Cisco Systems Inc. highlighted the storage cloud in their Virtual Computing Environment coalition (VCE) formed last year, which included an EMC-Cisco joint venture called Acadia. But those vendors were hardly alone in positioning enterprise data storage products as cloud-friendly. IBM, Hitachi Data Systems and NetApp Inc. also made the cloud a theme around product releases in 2009, and there was a plethora of "cloud" startups and services launched during the year.
Parallel cloud storage ecosystems evolving
A "true cloud" might be looked at as a single application such as Twitter, which serves hundreds, thousands or millions of users, said Wikibon analyst David Vellante. But in a data center, there might be hundreds or thousands of applications supporting a single organization. Users of the external cloud may be looking to reduce capital expenditures. Those deploying an internal cloud with storage automation might be looking to reduce operational overhead. "There are two types of ecosystems evolving," Vellante said.
For the purposes of this piece, these two ecosystems will be discussed separately, broadly divided into internal and external clouds. We'll explore which companies are embracing which approaches to cloud storage, as well as the next set of hurdles both concepts need to overcome to gain more widespread adoption.
For more on cloud storage:
1. Discover users' cloud computing concerns in Cloud storage adoption slow; cloud data backup leads the way.
3. If your organization is contemplating the cloud, you'll need some tips. Cloud storage: Five best practices for moving to the cloud will provide you the guidance you need.
4. Need information on service-level agreements? Find out what you need to know in Cloud storage service-level agreements (SLAs) specify uptime guarantees but not data availability.
5. Explore your cloud storage options.