Enterprises should check the scalability, manageability, performance and availability of a SAN solution before implementing it, says P P Subramanian

The perspectives of doing business in today’s competitive scenario are fast changing colour as enterprises extend their geographical boundaries to become global players. This transition has given rise to a new breed of enterprises commonly termed as e-businesses. But operating in an e-business environment has its own challenges as far as designing a storage system is concerned, for storing the vast amount of data and information that is critical for running businesses. Storage systems should be designed so as to meet the current and future needs of the organisation. In such a scenario, scalability is the core issue which needs to be addressed. Industry analysts like IDC and Forrester have predicted a continual growth of 50 percent per year in storage requirements. This would translate to a massive undertaking with far-reaching implications in terms of costs and manageability.

Storage should be networked
Today’s storage architectures are wasteful, unmanageable and non-standard. This is due to the dispersed nature of storage devices. Therefore, the key strategy for storage is that it should be networked. By networking storage architectures, firms can reduce expenses by 28 percent over a period of five years, according to Forrester.

However, as networked storage is the key to build a robust information infrastructure for the organisation, the storage solutions should offer customers open choices in deploying solutions like Storage Area Networks (SAN), Network Attached Storage (NAS), or a combination of both to meet their information needs.

Scalable
There are numerous benefits of implementing SANs, as they are scalable networks based on fibre channel protocols that support high-speed data transfers between servers and storage. In a SAN, high-speed networking allows storage to be shared and pooled, rather than be attached to each server directly. But in order to benefit totally from a SAN solution, customers should be offered scalability, centralised resources, data management, high availability and heterogeneous connectivity among others. SAN solutions should be infinitely scalable, with little impact on management of resources.

This is possible if the SAN solution is based on a switched-network SAN architecture. This allows users to scale to a much higher data capacity, while continuing to meet performance requirements. But the pertinent question is, how does the SAN switched fabric work to deliver the required scalability? Fibre channel switching architecture enables multiple 100 Mbps, non-blocking path connections, and as more and more ports are added to the switch, the aggregate bandwidth automatically increases, as each path delivers the same speed.

But switched fabric SANs place new demands on storage devices as they permit many more hosts to access any given storage port. As the number of users increase, the input/ output rates also increase and the access patterns get more dispersed. This can result in an overload of the internal share buses of traditional storage systems. Therefore, what is needed is an internal switched fabric design that delivers multiple, redundant, non-blocking paths between storage ports, multiple cache nodes and multiple disk array control processors. Besides, intelligence should be embedded into SAN solutions. This is primarily because enterprise storage is diversely different from desktop storage, it is differentiated by intelligence, which is delivered by the storage system. It should be coupled with a lot of other functionalities that directly impact availability of data and automatically allow the enterprise to back up data without affecting user performance.

Manageable
Management of storage resources is another critical area. A multiple vendor approach towards fulfilling storage needs resulted in various elements of the storage systems unable to talk to each other, restricting exchange of information. In such a situation, monitoring the storage system from a central point is almost impossible. Although the standards for storage systems are still in the evolutionary stages, some vendors have been working to allow inter-operability with each other’s solutions. Therefore, while choosing a SAN one should keep in mind that it should have an open architecture that allows it to be monitored centrally. This can only be ensured if the vendor offers a SAN solution that supports the management of SAN components of other vendors.

Some analysts point out that about 70 percent of large enterprises back-up only selective data because they lack the resources for a full back-up. An enterprise information storage system means investment in finding and retaining technical staff as well as investment in storage infrastructure that is changing by the day, and this is expensive. In such a scenario the services of Storage Service Providers (SSPs) come in handy. SSPs rent data storage on a per-user basis so that customers do not have to buy and manage their own facilities. Customers get a fast link to their stored data and the online tools they need to manage it. When storage needs increase, SSPs add new capacity. Therefore, the storage solutions that SSPs need should be scalable and those which enable them to configure and manage storage for their users remotely.

The bottomline of choosing a SAN solution is that it should be able to offer scalability, manageability, performance and availability, so that customers get maximum mileage out of their money.

P P Subramanian is the country manager (India) for Hitachi Data Systems