SANs and Sensibility

Storage Area Networks Offer Solution for Data Storage Growth

An IT manager would need to have spent the last year or two stranded on a desert island to have missed the media blitz surrounding storage area networks (SANs). SANs are the latest buzz in storage architecture and, depending on the analyst or pundit one reads, a panacea for companies struggling with data storage growth and its management costs.

SANs of the future will provide a highly manageable, scalable and available infrastructure for corporate information; instantly delivering data storage resources to applications and end users alike. They will make possible the sharing of data on a level unprecedented to date and, perhaps most significantly, will be a major factor in the essential infrastructure for robust e-commerce.

To prepare for that future, companies need to learn everything they can about SANs and the business problems that SANs may address. But, before moving forward with a SAN strategy, it would be wise to understand suitable technology alternatives. Seeking assistance from a service integrator can help match the business problems that need to be solved with the most appropriate technology and then to develop the solution that is ultimately deployed, including a program for ongoing support.

While significant cost advantages may accrue to SANs in the future, most authorities, including the Storage Networking Industry Association (SNIA), urge caution in making SAN acquisitions today. They note that the current crop of SAN-like products are not the "virtual storage pools" or "universal storage utility" that the architecture promises, ultimately, to provide. As with any emerging technology, IT professionals who invest in first-generation products must do so carefully if they are to avoid expensive upgrades or replacements in the comparatively short term.

Making intelligent decisions about storage architectures against the backdrop of media hyperbole and market promotion is always a challenge for IT professionals. With SANs, this challenge is doubly difficult. Understanding SANs requires a hybrid set of skills in network design and implementation, and in storage and storage management. These hybrid skills may not exist within the IT organization and often need to be cultivated through specialized training or by seeking outside assistance. Moreover, IT professionals may find it difficult to identify which "SAN-ready" products will work together to provide a truly integrated solution, especially in this nascent technology area where interoperability tests are being substituted for industry standards.

Against the backdrop of these technical challenges, it is possible to lose sight of the business objectives that a SAN (or any other information technology) is being considered to support. Modern corporations rarely deploy technology for its own sake. Technology acquisitions are expected to solve business problems, to have an articulated, and quantifiable, business value proposition. IT professionals need to be on guard against getting caught up in the enthusiasm surrounding SANs and to remain focused on the business objectives that technology enables.

All of the above suggest that, while targeted deployments have benefits, an integrated sensibility is required to make SAN acquisition decisions that will deliver a solid technical infrastructure to support mission-critical business applications. This article examines the current state of SAN technology and the role that a consultant/integrator can play in supporting business SAN initiatives.

Adolescent SANs

The current generation of SAN technology is best described as adolescent. In fact, there is little agreement among vendors about the definition of a storage area network. A survey of media coverage suggests that a SAN is a network of storage devices, separate and apart from the communications networks used to interconnect workstations and servers to each other, yet accessible to all servers. Typically, a specialized switch serves as the centerpiece of the SAN, providing connectivity to all connected devices and to servers via a high-speed, Fibre Channel, Gigabit-per-second (Gb/s), switched fabric.

SANs are conceived as an "open architecture," though there are greatly different interpretations of what constitutes "open." Some vendors refer to their current SAN offerings as "open" if they provide Fibre Channel connectivity. Others call SAN storage products "open" to connote that the storage is not "tethered" to a specific server, or to indicate that the physical storage can be partitioned and shared among different hosts. While these definitions are correct to a point, a truly open SAN enables direct access by any host system connected to the SAN to any data stored on any storage device that is part of the SAN.

The current generation of SANs do not provide a truly open storage environment as defined above. Even the most successful SAN-like products available today exact limitations based on the operating system of connected hosts. Observers claim that this situation will not be resolved for at least another 18 to 24 months, and probably through the introduction of a SAN operating system.

The adolescent SANs of today also lack a comprehensive "in-band management" mechanism. Fibre Channel provides a powerful interconnect capable of surmounting the distance and performance capabilities of SCSI, but it does not provide any integral mechanism for facilitating storage management. Thus, data security, file locking, device status monitoring, disk grooming and the myriad other requirements for "business class" storage management must be supplied through some sort of "out-of-band management" approach: typically, a number of management point products operating on a secondary network that surrounds the SAN itself. In-band management will be required before "true SANs" are delivered to the market, and is presently a focal point of activity both within SNIA and the Fibre Channel community.

Business Value Proposition

While the differences between the adolescent SANs of today and the mature SANs of tomorrow are profound, the current generation of SAN-like products can be of great value when they are deployed to meet specific business needs.

For example, some companies may only need homogenous server connectivity for their SANs to realize business advantages. Even current SANs, if properly deployed in a suitable infrastructure, can deliver the business value proposition sought from SANs. By divorcing storage from a server-captive configuration, and placing it in a switched SAN environment, companies are afforded enhanced data availability. In the event of a server crash, data remains available to other servers connected to the SAN.

Similarly, switched-fabric SANs enable inter-array mirroring and tape backup operations to occur without impacting production processing. That is good news for companies that want to lower the risk of data loss and improve recoverability in the case of a disaster event.

Finally, many (but not all) of the current generation SAN products are highly scalable. Servers do not need to be taken offline to add disks. This is a boon for any company feeling the pressure of 50 to 100 percent growth in data annually – or, in the case of certain ".coms," monthly, weekly or daily.

SANs cut to the heart of one of the dilemmas that has plagued distributed computing from the outset: storage management. By centralizing storage in a SAN, vendors argue, it is more readily maintained by a lesser number of qualified IT personnel. The extent of this total cost of ownership reduction argument, however, has yet to be demonstrated.

The business case for SANs has a few important caveats. SANs can represent a significant financial investment for a company – especially as they move out of the workgroup setting and into the mainframe/data center setting. Some of the risks have already been outlined above. Wrong choices today may lead to expensive upgrade and retrofit requirements tomorrow. Planning is key!

The complete financial investment required to field SANs goes beyond the cost of hardware acquisition. It includes "soft costs," including the training and development of a cadre of knowledgeable personnel who can select appropriate SAN products and ultimately deploy and manage the SAN. It may also include the creation or contracting of an interoperability test lab to confirm vendor claims about the capabilities of their products to interoperate with those of other vendors.

Even with all of these expensive preparations, there are few guarantees that the storage architecture will roll out without incident. Without solid experience to set expectations, companies must factor dollar exposures to project failures into their cost calculations.

Outsourcing Provides a Solution

Two alternatives exist for companies confronting the business need for a more resilient, scalable and manageable storage infrastructure. One is to bite the proverbial bullet. The company can do the best they can to live with the current storage infrastructure and its processes, or make incremental changes to one or the other, until SAN technology becomes more standardized. In the meantime, both business and IT must be willing to shoulder the burdens, in terms of cost and opportunity loss, that may accompany such a decision.

The second approach for companies that need storage infrastructure changes today is to seek independent, outside assistance to address the problem. This alternative enjoys several advantages over both the do-nothing and the do-it-yourself alternatives described above. Consider the following:

  • SANs convert storage from a business unit-owned asset to a business unit-shared asset. This represents a significant departure in many companies from a corporate culture of business unit empowerment and responsibility for which there may be no precedent. Thus, the organization may actually profit from an independent, outside perspective when developing new asset-sharing approaches.
  • In the absence of standards, there is no optimal SAN solution. Careful needs assessment, customization and integration by third parties is virtually a prerequisite.
  • As the SAN infrastructure scales to embrace data storage for an entire enterprise, it affects the enterprise at many levels. Business processes may need to be refined to capitalize on the strengths that shared data access provides. At the same time, new processes may be required to ensure the integrity and security of sensitive corporate data in a new storage infrastructure setting. Outsourcing to a qualified consulting organization can smooth the transition by leveraging the consultant’s experience in other companies.

    However, a future-oriented solution may require more than a single vendor’s technical support team can provide. Here’s why:

    A SAN is an unusual technology that, by its nature, limits the capability of any single vendor to provide a best-of-breed solution comprised entirely of its own products. Even the most proprietary SAN solutions offered today contain the components of multiple vendors. Thus, the expertise that vendor technical sales personnel possess in their own products rarely extends to the other products that comprise the SAN they are fielding. This can lead to finger-pointing and costly delays when implementation issues arise – immediately or in the future.

    It should be noted that most major players in the SAN market have acknowledged this deficit and are depending extensively on their channel sales organizations (resellers, ISVs, etc.) to deploy SAN technology. International Data Corporation analysts have argued persuasively that SAN revenue will be driven largely through channel, rather than direct, sales. The reason for this conclusion: Vendor direct sales organizations rarely possess adequate personnel to provide the "customer face time" required by so complex a technology as SANs. It is believed that resellers, who have fewer overall customers and whose sales and support organizations are focused either geographically or in specific vertical market segments, will be able to provide the greatest measure of customer hand-holding that is prerequisite to a sale.

    Resellers, however, confront many of the same limitations as their vendor business partners when it comes to SAN technology. They are generally expert in the products of the vendor and less knowledgeable about the third-party gear included in the vended solution. All of the interoperability testing performed by vendors prior to the fielding of a solution is meaningless the first time that a new problem arises.

    Many vendors and resellers also lack the hybrid skills set required for successful SAN deployment. Infrastructure expertise, both in storage and networking, are required to design a suitable SAN because SANs blur the line between these technological disciplines. In the few cases where cross-discipline knowledge and skills are present, a kind of technological myopia may persist, regarding the range of possible alternatives – usually along vendor-specific lines.

    The tendency of vendors to favor their own branded solutions goes without saying, of course. Competition will ultimately benefit consumers by improving technology. As stated previously, homogeneous SAN solutions (i.e., all one vendor, all one operating system, all one storage product solution) may provide exactly the right fit for a business unit within a company. A problem arises when, over time, a company seeks to scale a SAN to a heterogeneous enterprise environment. Some vendors of storage arrays and servers see this possibility as a threat to their own profitability.

    For example, a large-scale storage array vendor may be amenable to a SAN solution centered around its storage array products. However, the same vendor must acknowledge that open SANs will ultimately provide a vendor-agnostic SAN fabric that may eventually see a competitor’s product on the same floor as the vendor’s array. SANs have been termed the "great leveler" for just this reason. One SAN switch provider has remarked that once a company sees that "Generic JBODs" provide exactly the same service levels as "Name Brand Company’s Expensive Array," he is going to realize that he has been paying too much for storage. Standards always create product commoditization and drive down prices. Robust SAN standards, still a few years away, promise to do this in the array business, voiding customer locks that certain vendors have always enjoyed.

    Similarly, server vendors recognize SANs as a potential threat to their business that must be controlled. Between 60 and 80 percent of the revenue from a server sale today is derived from its associated data storage components. SANs will ultimately take storage out of the box and place it behind the SAN switch. Given this projection, it is easy to see why a vendor would promote a SAN solution that depends on its own server components for required functionality.

    The point is that vendor/reseller-provided solutions are likely to be influenced by numerous factors other than the business requirements of the prospective customer. For this reason, a company would be better served by outsourcing its SAN design, development and implementation work to a vendor-neutral third party.

    Critical Success Factors

    Some of the criteria that should guide the selection of a storage infrastructure consultant can be inferred from the above discussion of vendors and resellers. Quickly summarized, these include:

  • Vendor Independence. The consulting organization should be able to evaluate business requirements and suggest best-of-breed solutions without bias. This is not the same as suggesting that the consulting organization should have no ties to the industry. In fact, consultants should partner with the broadest possible spectrum of industry-leading product vendors in order to provide a fair and factual representation of the benefits and drawbacks of each approach. This relationship profits vendors as well, since it ensures that their technology will receive a fair hearing from the prospective customer.
  • Enterprise Infrastructure Expertise. The consulting company should possess hands-on experience not only with primordial SAN technology, but also with other aspects of enterprise infrastructure, such as mission-critical applications, networks and server technologies. The skills and knowledge derived from SAN-related engagements need to be 1) integrated into the knowledge-base and methodology shared by all field consultants within the organization, and 2) transferred to client company personnel over time in the form of training and education. In these days of IT personnel shortages, it is not sufficient for a consulting company’s entire practice in the realm of storage to rest on the availability of a few knowledgeable personnel.
  • Storage Infrastructure Rather Than SAN Focus. By current estimates, SANs will likely proliferate over the next decade. However, in most businesses, SANs will coexist for the foreseeable future with other data storage architectures. Consulting firms need to have a broad expertise in storage architecture to facilitate the management of such a complex environment. Be wary of any firm that proposes a SAN as a panacea for every business-computing problem.

    Outsourcer Methodology Is Essential

    In addition to the derivative criteria described above, two additional factors should also be considered when selecting a consulting organization. First among these is methodology.

    SANs are not an end in themselves. They should be considered as a single arrow in the quiver of solutions offered by the consulting firm in response to business problems. In some cases, solving the underlying storage-related cause of a specific business problem will take the form of a high-speed, point-to-point, Fibre Channel interface between a particular server and an array. The words "problem solving" imply a methodology for delivering solutions.

    Effective consulting firms derive methodologies from experience – both in the lab and in the trenches. Methodology provides access to project leaders and consultants to the collective knowledge and experience of the organization derived from its engagements. To most firms, it is a powerful discriminator.

    When evaluating a consultant as a potential partner in a SAN implementation, examine the firm’s methodology closely. It should contain the following components, at a minimum:

  • Needs Assessment. There are numerous approaches to identifying the business problem or requirement that is driving a technology search. The consultant should have an approach that embraces problem definition, current business process modeling, cost analysis, solution budgeting, solution objectives setting, and service level requirements setting. In practical terms, the consultant should be able to understand the problem, contextualize it in business and budgetary terms, and identify the requirements of a solution to resolve it. In the case of SANs, the consultant should be able to assist in the preparation of requests for proposal from vendors and reseller/integrators that articulate objectives and critical success factors. The consultant should also be prepared to aid in the evaluation of proposals, if desired, and to evaluate the technical solvency of the proposed storage topology.
  • SAN Design. In some cases, the consultant may also serve as an integrator, especially if all required ingredients of the solution cannot be obtained from a single source. The methodology should provide standards for articulating solutions in terms of topology, architectural components, performance characteristics, and support requirements. While problem solving methodologies suggest a tactical focus, consultants should provide, as part of their deliverables, a strategic plan or road map suggesting how current solutions may be scaled and integrated as company needs change over time. Future solutions should also reference this strategic plan.
  • Implementation and Verification. The consultant/integrator’s methodology should provide project management and implementation guidance. Such techniques as piloting, parallel testing, verification and cutover should be defined for a SAN implementation in at least as much detail as one would plan for a major network or systems infrastructure change.
  • Performance Measurement. No SAN implementation is complete without comprehensive performance measurement both at the time of deployment and on an ongoing basis, thereafter. Defining what is to be measured and how it will be measured should be part of the methodology and documentation, and proscribing the specific test and measurement regime should be a deliverable for the customer.

    Education and Maintenance

    Finally, in addition to methodology, the training and education offerings, as well as the ongoing service and support capabilities, of the consulting firm should be key factors in consultant selection. Training and education services are a guarantee of knowledge transfer and there is no greater example of the need for effective knowledge transfer than the deployment of SAN technology.

    For SAN deployments to be successful, they must seem to be evolutionary, rather than revolutionary. Company personnel must be facilitated in their transition to new data access methods: an important training requirement. Of equal importance, IT personnel must be educated about SANs, how the technology works and what problems it can solve. This education process begins during needs assessment and may include a program of formal instruction including lab work with actual SAN technology. The purpose should not be to press SANs as a cure-all, but to facilitate an understanding of the storage infrastructure and the requirements for its effective management.

    Support services, once the project is complete, should also be a deciding factor in consultant selection. Support and maintenance services are critical for SANs because it is often the consulting firm that engineers a solution, rather than a vendor. The firm should be willing to assume responsibility for serving as a single point of problem resolution for any difficulties that may arise.

    The Difference Is Simple

    A traditional systems integrator focuses on component technology – software, storage, servers, networks – and works to knit them together as part of a defined solution. By contrast, a service integrator, such as storage network services, focuses its efforts in the areas of consulting and education, first and foremost. It is our objective to help companies define business problems and to understand, plan and act upon the alternatives.

    Given the critical nature of storage area networks – the ongoing development of standards and technology in the field, the conflicting information propagated in the trade press and in marketing literature, and the "religious wars" that occasionally break out between SAN vendors – service integration is a powerful approach; an approach that delivers sensibility to SANs.