iSCSI specification complete, clears way for products

The draft specification for transmitting SCSI commands over IP networks has passed the final hurdle on its journey toward ratification, opening the door for vendors to begin shipping products based on the technology blueprint.

The Internet Engineering Task Force (IETF) said today that it completed work on the Internet Small Computer Systems Interface protocol, or iSCSI, and will now assign a request for comments number to it.

"Everyone's been chomping at the bit to get products out. I think once we start shipping products, [market adoption is] going to happen pretty rapidly," said Bill Lynn, co-chairman of the Storage Networking Industry Association's IP Storage Forum.

ISCSI is considered by some to be a key technology for increasing the deployment of storage-area networks (SAN) because it uses ubiquitous IP networks. The specification dictates how software takes SCSI data packets and wraps them in TCP/IP commands in order to transfer them over intranets and manage storage over long distances.

Cisco Systems Inc. said it will support the request-for-comments version of the protocol in its next driver, feature and firmware upgrades, expected within the next six months or so. IBM and Intel Corp. are among other big-name vendors supporting the new specification.

Last year, Cisco, IBM and switch-maker Nishan Systems Inc. all rolled out iSCSI products based on different versions of the draft for IP-based SANs and so-called hybrid Fibre Channel-to-IP SANs. But a market for iSCSI has yet to sprout, and some say that's because current products based on different draft versions made interoperability difficult. That problem is expected to be rectified with the new final draft.

Experts agree that large iSCSI target devices are a crucial element to adoption in data centers. IBM recently shut down production on its only native iSCSI target device, a small disk array (see story).

Michael Peterson, an analyst at Strategic Research Corp., a network storage management market research firm in Santa Barbara, Calif., said it will be five years or so before the iSCSI market reaches anything close to what Fibre Channel SANs are today. Peterson cites latency and reliability issues related to transmitting data over IP networks.

Ratification of the specification is a necessary step, "but it's not the only step or the most important one that speaks to market adoption," he said. "Relational databases are all about performance and latency, and that's 65% of the data behind servers. And that's all about Fibre Channel.

"IP storage is going to see a 50% to 60% market penetration eventually," but that's five or six years from now, Peterson said.

Currently, Fibre Channel exists in more than 25% of the data centers of Global 2000-type companies. That figure is expected to grow to 45% in the next several years. IP storage, which includes Fibre Channel over IP and Internet Fibre Channel Protocol, must still overcome problems with latency and security.

"IP SANs will open new markets and expand businesses, but they still have to have all the fundamentals in place as far as the applications and drivers. ... If it's still easier for a customer to do direct-attached storage, why change?" Peterson said.

Jamie Gruener, a storage networking analyst at The Yankee Group in Boston, agreed.

"Yeah, the products are on the way, and there are some that are here already. But there's still the question of, Why do I do this today, or even a year from now?" Gruener said.

Copyright © 2002 IDG Communications, Inc.

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