Global Storage Networks: Their Time Is Now - Industry Trend or Event

Computer Technology Review, Feb, 2001 by Dr. Kanwar J.S. Chadha

Looking at the advances in IP networking, storage-oriented carrier networks, storage software and optical SAN transport technologies

As if one needed more proof of the tremendous impact of the global data explosion, researchers at the University of California are predicting that more data will be created in the next three years than in all of previous human history.

In a connected digital world, managing, accessing, copying, backing up, protecting, storing and moving information is more important than ever.

At the enterprise level, research firm International Data Corporation estimates that storage demand for an average Fortune 1000 company will grow an astonishing 650%, from 40 terabytes to 300 terabytes, over the next five years. E-commerce, both business-to-business and business-to-consumer, is leading the way to an environment where virtually all data is housed electronically. Sophisticated customer relationship management (CRM) applications rely on voluminous customer records. Next-generation scientific and technology breakthroughs, such as sequencing the human genome, hinge on the ability to quickly, securely and affordably access vast mountains of stored data. Even governments, traditionally the last large organizations to embrace new technologies, are slowly but surely migrating to all-electronic storage.

The data storage explosion is not confined to businesses and governments. As paper copies of medical, financial and legal records give way to digital documentation, personal storage will grow exponentially. In fact, some experts believe that in the near future, American citizens will, on average, possess a startling one terabyte of stored information. The latest Census calculated that the U.S. population now exceeds 281 million people. For the quantitatively inclined, that means that personal storage in the U.S. will soon require 281,000,000,000,000,000,000 bytes of data.

The Emergence Of SANs

Fibre Channel storage area networks (SANs) have become the storage networking choice for managing the data explosion, ensuring high availability of data and running data-intensive applications. SANs greatly alleviate local area network (LAN) congestion because they allow for campus-wide storage access and separate storage-oriented data, especially large block, streaming, and large file data, from the LAN.

However, since Fibre Channel SANs only extend about six miles, SAN data is inaccessible to remote servers and other non-local computing resources.

IT-savvy enterprises seek to locate resources where they are most needed and most economical and try to fully utilize existing capacity before adding additional resources. Indeed, most companies would welcome the opportunity to locate storage resources where space and labor are readily available and affordable. Today's SAN technologies often make these goals difficult--if not impossible--to achieve.

Key storage applications such as disk mirroring, backup and recovery are becoming mission-critical for ensuring ecommerce and enterprise continuity. Geographically dispersed companies incresingly seek to deploy these applications remotely over long distances. Moreover, the performance of many of these applications, and mirroring in particular, depend on low-latency networks. Constrained by SAN distance limitations and latency inducing networks, most companies find it difficult to achieve the benefits of cost-effective long distance storage solutions.

The next step in the evolution of storage networking is clear: global storage networks that provide access to stored data regardless of location. Global storage networks will greatly enhance data availability, power critical business and consumer applications and promote the nascent storage outsourcing movement.

Building a global storage network, however, presents more than a few challenges. It requires flexible, open SAN transport devices that connect currently isolated SAN islands over Internet Protocol (IP)-based networks, carrier networks optimized to carry storage data, software to manage the storage domain over long distances and the integration of advanced optical networking technologies.

SAN Over IP Requires Flexible, Open Solutions

IP networks, ideal for messaging, have emerged as the preferred and most cost-effective networking solution. However, they do not meet the quality of service, data security and high-bandwidth demands of storage applications. The IP transport layer that sends data packets and monitors delivery is not designed to effectively manage the massive quantities of data that storage applications utilize.

Current attempts to connect local SANs over distance usually require traffic to be routed through servers that interface to the wide area network (WAN). These topologies require expensive, high-end systems with extensive memory and extremely fast processors. This approach is cost-prohibitive and sacrifices flexibility--the key component to successful SAN over IP-network transport.

Instead of deploying a makeshift fix that is based on general-purpose servers acting as routers, dedicated SAN over IP switches and routers can lay the groundwork for a truly global storage network. These devices encapsulate or "wrap" Fibre Channel frames into IP packets to deliver block-level SAN data over WANs and metro area networks (MANs).