Make way for IP SANs

With IP storage, it's no longer a question of but . With technology and marketing giants like Cisco, IBM, and Intel leading the charge, IP storage is inevitable.

But it's not just marketing muscle that will enable IP storage area networks (SANs). Whether it's file-based network-attached storage (NAS) or block-based SAN, IP storage has a value proposition that's extremely compelling to IT managers with tight budgets: the ability to leverage existing hardware and software as well as technical skills, while delivering performance that will likely be sufficient for most storage applications.

IT managers realize that, but they need to know when they will be able to build end-to-end IP SANs that include iSCSI host bus adapters/network interface cards all the way to storage subsystems with iSCSI controllers.

You can actually build a partial "pre-iSCSI" SAN today with equipment from Cisco (storage routers), IBM (disk arrays), Nishan (switches), FalconStor (software), and others. What's missing are iSCSI host bus adapters (HBAs) or network interface cards (NICs) that offload cumbersome TCP/IP processing from the host CPU, which will be necessary to achieve the end-to-end performance that most storage applications require.

A number of networking and storage vendors are promising iSCSI HBA/NIC cards by year-end. However, that usually means "we'll show it at Comdex and ship a few to our closest OEM partners for Christmas."

So, when will you be able to build an end-to-end IP SAN? Assuming that HBA/NIC vendors demonstrate high-speed interoperable products in the Comdex time frame, that they meet performance expectations, and that production shipments begin in the first quarter of next year, I'd say mid-2002 is a good bet. By then, a lot of disk controller and array vendors will have followed IBM's lead, and you should have plenty of choices at the subsystem level.

However, analysts predict a relatively slow adoption rate for IP SANs, with little impact on the growth rate of Fibre Channel SANs over the next few years (see chart).

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Dave Simpson, Editor-in-Chief

This article was originally published on June 01, 2001