iSCSI spec ratification clears way for product surge

The draft specification for transmitting SCSI commands over IP networks has passed the final hurdle on its journey toward...

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 yesterday 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 to transfer them over intranets and manage storage over long distances.

Cisco Systems said it would 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 are among other big-name vendors supporting the new specification.

Last year, Cisco, IBM and switch-maker Nishan Systems 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 existing 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 centres. IBM recently shut down production on its only native iSCSI target device, a small disk array.

Michael Peterson, an analyst at Strategic Research, a network storage management market research firm, said it would be five years or so before the iSCSI market reaches anything close to what Fibre Channel SANs are today. Peterson cited 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%-60% market penetration eventually," added Peterson, predicting that this would happen in about five to six years' time.

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