Finally, affordable SANs - Storage Networking

Computer Technology Review, Oct, 2003 by Ellen Lary, Richard Lary

During times when infrastructure spending is flat or reduced, storage management is at the center of increasingly complex IT problem. Today, most of the storage deployed in small and large businesses is directly connected to individual server groups. Direct-Attached Storage (DAS) is expensive and does not scale easily. DAS is also inefficient because it cannot be shared among servers, resulting in low utilization. All the while, applications continually demand more from their storage systems, putting increasing pressure on servers and storage products as their capacity, availability, backup, and disaster recovery needs intensify.

Storage consolidation using Storage Area Networks (SANs) does provide a solution; however, there are significant barriers to deploying SANs in many environments Conventional Fibre Channel SANs are expensive because they are built from relatively low-volume components and cannot be managed in an integrated manner. To attract the mid-range storage market and provide a solution for business critical applications, a consolidated storage solution must deliver the features of today's SANs ae but at a significantly lower cost and with less management overhead.

Fortunately, the advent of Ethernet-based SANs and the iSCSI standard means that it is possible to combine the simplicity of Ethernet networks with the advanced storage features mandated by mission-critical applications into a reasonably priced and easy-to-manage product.

Storage Consolidation

Storage consolidation ae a single, large, shared pool of storage that can be accessed by a variety of heterogeneous servers and applications on a network ae is an architecture that allows storage devices and servers to be acquired, managed, and upgraded independently. Centralized storage management can result in lower management costs, high availability, easy scalability, and efficient storage space utilization, in addition to simplified backup and disaster recovery strategies. With consolidated storage, costs can be shared by the various departments and entities utilizing the storage. One method of consolidating storage is to set up a SAN.

A survey of 86 companies, conducted by Robert W. Baird, shows the typical reasons customers install a SAN (see Figure 1).

[FIGURE 1 OMITTED]

Barriers to Using SANs for Storage Consolidation

What prevents the widespread use of today's SANs in the data center is the cost and complexity of deployment and maintenance. To implement an overall solution, many individual hardware and software components must be installed and managed in a synchronized fashion. The burden of supporting and upgrading many disparate elements is intimidating to organizations without large staffs and budgets. Often, the hardware and software do not operate in an integrated manner. Implementers address the problem with customized management solutions, which add to the burgeoning problem of heterogeneous or non-standard storage management. Often, SAN configuration complexities require that IT managers learn new tools and technologies in order to manage the various hardware platforms and the multitude of management interfaces created as a remedy for ongoing storage management problems.

These costs and complexities are acceptable in a mission-critical application environment, which is where Fibre Channel SANs have been beneficial. However, the typical environment for business-critical applications generally does not have a system management budget that can handle these concerns. It is not unusual for storage management to be part-time job for one or more people. Simply stated, a SAN cannot be used as a consolidated storage solution for mid-range storage unless it can deliver high-end features at significantly lower cost and with less complexity than the offerings available today. In addition, storage configuration must be simplified and day-to-day management tasks minimized, while avoiding the use of specialized networking technology that requires extensive training.

The survey previously referenced also reveals that 62% s of respondents cited high initial deployment costs as a main impediment to the deployment of SANs for mid-tier servers. One Fortune 500 manager said, "Our large, redundant, expensive SAN is overkill for this class of server and is, therefor, not a cost-effective solution."

Consolidated Storage for Business-Critical Applications

Today, there is a growing need to provide a consolidated storage solution for business critical applications with the same functionality as solutions geared toward mission critical applications ae but at a significantly lower cost and without excessive administrative overhead. This represents a business opportunity for an affordable, mid-range storage solution that protects data and also delivers advanced storage management features, such as seamless expandability, automatic load balancing, disaster tolerance, and replication. Such a solution would enable businesses to move away from DAS and enjoy the benefits of consolidated storage without the cost and complexity of conventional high-end storage products.