Commentary: IBM's smart storage move

By Robert Passmore, Gartner Analyst

Gartner believes that IBM has made a wise move in announcing low-end storage area networks using SCSI running over TCP/IP.

Some pundits have hyped iSCSI technology--that is, SCSI (Small Computer Systems Interface) via TCP/IP--as a replacement for Fibre Channel that's easier to use and less expensive. The use of the ubiquitous TCP/IP could enable businesses to fill all of their SAN needs--infrastructure, management tools and people--with products and services from vendors already in place.

However, Fibre Channel will

	See news story: IBM adopts new storage network standard

be difficult to dislodge from enterprise SANs for several reasons. Fibre Channel adapters have much higher performance and lower overhead than their NIC (network interface card) counterparts. Moreover, finishing the standards efforts for iSCSI and implementing higher-performance NICs will take time. Finally, SANs based on Fibre Channel are already established in the market, and they work well.

Starting with those disadvantages, iSCSI vendors could take Fibre Channel on by leaping over it technologically--for example, by developing SANs that run at 10 gigabytes per second before such Fibre Channel products become available. However, that strategy would be a bit of a gamble.

Instead, IBM has accepted the limitations of iSCSI by targeting its products based on that technology specifically at problems that Fibre Channel does not address. Workgroups and small departments cannot justify the expense of bringing Fibre Channel-based SANs to the desktop, but the infrastructure is in place to support TCP/IP. All that is required is the addition of a small piece of software in each of the client platforms that will use the new protocol via existing NICs. IBM's new iSCSI Storage Appliance does the rest by providing the centralized storage for those small SANs.

Thus, IBM continues to promote its own Fibre Channel solutions for enterprise SANs against rivals such as Compaq Computer, EMC, Hewlett-Packard and Hitachi Data Systems. And IBM brings iSCSI and its block-protocol SANs to a market now served only by network-attached storage with its file-serving protocols. EMC, IBM, Network Appliance and others all sell network-attached storage appliances, but at least for the time being, only IBM will offer the iSCSI SAN alternative to workgroups and small departments.

(For related commentary on the NAS market, see TechRepublic.com--free registration required.)

Entire contents, Copyright © 2001 Gartner Inc. All rights reserved. The information contained herein represents Gartner's initial commentary and analysis and has been obtained from sources believed to be reliable. Positions taken are subject to change as more information becomes available and further analysis is undertaken. Gartner disclaims all warranties as to the accuracy, completeness or adequacy of the information. Gartner shall have no liability for errors, omissions or inadequacies in the information contained herein or for interpretations thereof.