ISNs Go Beyond SANs

Posted on November 01, 1998

ISNs Go Beyond SANs

By Jeffrey Allen

Networks often have inadequate bandwidth for storage transfer and data sharing. As storage needs increase, companies add more devices, causing further congestion and increasing the risk of downtime and subsequent revenue loss. The situation is further complicated by interoperability issues among incompatible heterogeneous systems.

Inevitably storage subsystems run into bandwidth limitations--not to mention capacity, I/O, host and application support, connectivity, and other constraints. When those limits are reached it can be very difficult to add resources in desired increments. It is often impossible to take advantage of the aggregate performance capabilities of the attached subsystems without tedious and difficult partitioning. The only solution is to buy additional, isolated server arrays--increasing both cost and administrative complexity.

Enterprises need scalable solutions that can work with heterogeneous systems; simplified management and unlimited scalability; transparent "anytime, anywhere" access to information, without bottlenecks; and information sharing in order to effectively manage data warehousing, OLTP, and business continuance applications.

An "intelligent" solution is needed. An intelligent storage network (ISN) combines the traditional attributes of high-end storage systems (reliability, availability, performance, and manageability) with the connectivity and distributed access benefits of network computing. The concept of a storage area networks (SAN) is a step in that direction.

In a SAN, storage arrays are linked to form a storage subsystem on the LAN. Because a SAN uses storage-specific protocols, it is faster than the rest of the LAN and can support heterogeneous platforms.

ISNs are fundamentally different from SANs. A SAN is basically about connectivity. But connectivity alone doesn`t solve your business problems. That`s where the intelligence in ISNs comes into play. The network overhead is handled where it should be at the network level freeing application servers to process applications faster. With an ISN, the storage network becomes a provider of services to the application servers.

An ISN allows you to make data available to application servers as needed at storage rather than network speeds. It also allows better load balancing since system resources are distributed enterprise-wide within the SAN, and because heterogeneous systems can be interconnected, you can select the optimum hardware for each application. You`re not forced to standardize on an operating system that won`t scale or to write emulation software to run on legacy hardware. You can integrate all existing equipment and add new components as necessary. Your network becomes a utility: You plug in what you need, when you need it.

There are a number of key technologies and capabilities that are required to transform the vision of the ISN into reality:

- Intelligent storage servers run a full operating system that controls storage functions. The "intelligence" of the server enables you to streamline existing processes and procedures to save time and money, improve availability, and increase data accessibility.

This means you can cut costs and optimize the use of each machine, providing better service to all users. Further, by relying on network-based software and backplane-based firmware, the system can accommodate upgrades more easily.

- Information sharing--the ability to directly and seamlessly transfer information among different server platforms--is required to ensure that enterprise information is always current and easily accessible and to help make more efficient use of expensive computing resources.

Consider an example from the retail industry. Most major retailers are building huge data warehouses because success or failure hinges on the quality and quantity of SKU data. Without information sharing, heterogeneous systems can`t quickly share data, so it takes longer to load the warehouse with fresh data. Without data sharing, it took a major retailer 36 hours to load its data warehouse, restricting this operation to weekends. With data sharing, it took only six hours, enabling nightly updates.

- Fibre Channel delivers the network-oriented, high-performance backbone needed for heterogeneous connectivity, availability, and scalable performance. It operates over fiber-optic cabling at distances of up to 10 kilometers, providing flexibility in how it is deployed. It supports multiple interoperable topologies, including point-to-point, arbitrated loop, and switching, so it works with existing and emerging technologies. It offers several qualities of service for network optimization. And with support for large packet sizes, Fibre Channel is ideal for video, graphics, and mass data transfer applications.

Fibre Channel switches and hubs are network building blocks for interconnecting diverse servers. These devices allow you to attach storage components to virtually any system on the network. And Fibre Channel`s ability to operate over much longer distances than SCSI makes it ideal for off-site mirroring.

- Building block components are the raw material of assembling scalable storage solutions. The alternative is a monolithic approach, and all the problems that come with it.

Consider an example from the manufacturing industry. Manufacturers are constantly looking for new efficiencies to streamline production. With a building-block approach to storage, users can evolve processes gradually and incrementally, without taking the factory down. They can re-deploy hardware from one department to another to match new processes. And they can take full advantage of cross-departmental applications such as product data management (PDM), which requires a smooth flow of information throughout the supply chain.

This modular architecture enables users to protect investments while upgrading to the latest technologies quickly and cost-effectively. For example, new disk drives or upgraded I/O boards can be implemented as soon as they become available, without requiring the purchase of an entirely new system or "forklift" upgrades.

This is only the beginning. In the future, an ISN can be the basis of a new class of storage applications, made possible by better management of computing cycles.

Jeffrey Allen is the senior director of marketing for the network storage group at Sun Microsystems, in Newark, CA.