Standard approval big step for SANs

A new standard for storage area networks is about to be approved which could be a godsend for firms struggling to find the funds for a full storage management upgrade.

ISCSI, the storage-over-IP standard that has been in the pipeline for several years, is soon to be officially approved by the International Engineering Task Force and could be a godsend for storage users who want a SAN — a network devoted to storage that’s accessed by switching technology — but haven’t been able to justify the cost of a changeover.

ISCSI is an advance on SCSI (small computer system interface), the long standing interface between servers and networked storage devices that has been losing ground to the alternative fiber channel technology because of the latter’s superior speed. Under iSCSI, SCSI commands are sent over IP networks.

While it won’t be taken up immediately, iSCSI will be common in the storage world in a few years, says IDC storage analyst Graham Penn.

“There’ll be some implementation on a small scale but I don’t expect iSCSI to ramp up until next year.”

After implementation by early adopters, its use will begin to increase in volume next year and by 2005 it will be mainstream, he says.

That doesn’t mean fiber channel is on the way out, however.

“For organizations that have already installed fiber channel, iSCSI won’t push it out of the data center within the next five years.”

For those who use fiber channel to move data over long distances for replication or publishing, iSCSI could work, Penn says.

A big potential market for iSCSI is organizations still using direct-attached storage, for whom moving to a SAN would be impractical or too expensive.

“When iSCSI is available, organizations will be able to use their inhouse IT staff to install it.”

It is in such enterprises that iSCSI will be used for data centers, he says.

Fibre channel will never be supplanted by iSCSI, he says. “When Cisco (Systems Inc.) entered the storage market, it decided to go with storage-over-IP, but acquired Andiamo because of its fiber channel technology. Its push is in fiber channel switches, but that doesn’t mean they’ve abandoned storage over IP, but big SAN users are locked into fiber channel for the next five to eight years, so if Cisco is to be a player it needs to be in fiber channel.”

In the future, switches will be able to handle both fiber channel and IP — it’s about adapting the best technology for what the business has.”

Fibre channel over IP is in use at some organizations, but any iSCSI in New Zealand is still in the lab, as the standard hasn’t been ratified, Penn says.

However, in the U.S. and Europe some businesses are running iSCSI, because some vendors are already offering products based on the technology.

Fibre channel was developed to bring storage networking speeds up to 1G bps, three times what SCSI offers. Penn says it is now at 2G bps and is likely to be up to 10G bps by 2005.

“ISCSI is at 1G bps and will move rapidly to 10G bps — there are some latency issues with it, but the technology problems will be solved.”