Three quarters of companies are either currently using or plan to use public cloud storage offerings. What's more, all organizations with more than 500 employees are using or planning use of public cloud storage, mostly for e-mail, data protection and front-office applications like CRM, especially SaaS-based CRM solutions such as Salesforce.com. That's the upshot of a recent survey of 133 CIOs\/CTOs and their operations staff in North America conducted by SNIA (Storage Networking Industry Association) and our industry analyst firm, Storage Strategies NOW. The survey paints a picture of a technology that's poised for takeoff \u2014 if providers can overcome user apprehension over two big concerns: security and performance. Anand Kapoor, vice president of technology of WNS Global Services, a business process outsourcing firm in Mumbai, India, puts it this way. "Generally you see two sets of early adopters: smaller enterprises and SMBs that cannot afford the redundancy that an enterprise-class infrastructure would cost, and larger enterprises that need rapidly scaling infrastructure that is managed by organizations with the core competencies related to storage," says Kapoor. Making the Cloud Storage CaseIn a way, public cloud storage is like any outsourcing decision. Companies are faced with ever increasing storage requirements, many of which imply permanent retention of archives. So is it better to leave long-term storage management for generic applications like e-mail and CRM to external organizations whose primary business is providing those services, leaving IT more time to focus on critical business applications? Clearly, many CIOs and CTOs believe it is. Cloud access appliance manufacturer Nasuni's CEO, Andres Rodriguez, likens public cloud storage to an electric utility. "You wouldn't try to build and manage a power generating station in your back yard, so why try to recreate the economies of scale that the cloud storage provider has available?" he asks. Speed of deployment is another issue, says Hisam Ahmad, global head of architecture and engineering for T-Systems, a hosting service provider in Bonn, Germany, which both uses and provides cloud storage access. "It takes time for an IT organization to plan for increased data center infrastructure, find a vendor and finance a storage acquisition, and then it has to wait months for installation," he says. "We are seeing end-user organizations going around IT and directly contracting cloud storage and using it within days if not hours." Potential Cloud PitfallsWith many good reasons to deploy public cloud storage, what's the downside? Fear of security breach, loss of control and access to critical data are major concerns, according to the SNIA\/SSG-NOW study. Perpetuating these issues is the lack of a standard for public cloud data interchange. Each provider has its own version of an HTTP command structure that is foreign to existing applications. Modying existing applications to use a proprietary public cloud is not feasible, so this relegates public cloud to only those applications that are already cloud ready. SaaS providers and Microsoft, for its Exchange email offering, have transparent interchanges developed and massively deployed, for example. Likewise, data protection and disaster recovery products that have a public cloud interface are available from a number of vendors and cloud service providers such as Nasuni and TwinStrata. WNS Global is addressing the security issue, according to Kapoor. "At WNS, our primary concern is the security of data. All customers are segregated first at the network level and then, using technologies such as Multi-stor, we make sure there is complete segregation at the storage level," he says. "As a result there is no part of the infrastructure that overlaps between customers." So what will it take to make cloud storage viable for applications beyond e-mail, CRM and data protection? The answer is simple: Cheap bandwidth. As tablets and smart phones become everyday business tools, new applications in many organizations will embrace browser-based HTTP application interfaces to primary storage. As more of these devices are deployed in business-critical applications served up over the Web, in a way, cloud storage automatically becomes primary storage, particularly if the storage is not maintained on the local device. This is a good thing, until you run out of bandwidth. SSG-NOW is involved with a number of companies that are working at various levels within the TCP\/IP infrastructure and it is our opinion that there is plenty of headroom in the existing and developing network infrastructure to handle the increased loads that the new generation of client devices will require. In Search of a StandardIn addition to bandwidth, respondents to the SNIA\/SSG-NOW survey were adamant that standards development is essential. Nearly four out of five respondents (78 percent) indicated that standards were either very important (47 percent) or important (31 percent) to their future deployment. The greatest support (53 percent) was for the SNIA CDMI (Cloud Data Management Interface) standard. This support notwithstanding, it is our opinion that the work being done by the Open Stack interest group \u2014 supported by Dell, Rackspace, NASA, Citrix, Cisco, Canonical and over 50 other organizations \u2014 will deliver the most useable interface code the soonest, offering a de facto standard that is likely to precede ISO standard adoption by years. The code can be obtained under the Apache 2.0 open source license. (Information on the organization can be found here).Short of widespread adoption of a standard set of interfaces, cloud storage users have access to a number of virtual and physical appliances to connect their existing systems using block storage or file storage interfaces. These provide several advantages. First, the appliance provides an interface to cloud storage as if it is any block or file storage system. Second, an appliance that provides a transparent interface to a number of cloud service providers is an insurance policy against either technical or contractual difficulties with a service provider. This has been referred to as the Hotel California syndrome - you can check out but you can never leave.Finally, these appliances offer WAN acceleration features like compression and network flow optimizations that address the bandwidth cost issue.With increased pressure to provide more storage at lower or similar capital and operating expenses, the catalyst to adopt a public cloud strategy will continue to increase adoption across organizations of all sizes. James E. Bagley and Deni Connor are senior analysts with Storage Strategies NOW, an industry analyst firm in Austin, Texas. You can reach them at firstname.lastname@example.org and email@example.com.