Block-level storage transmission. It's the thing that has separated the men from the boys in storage networking, according to many industry pundits. DASD does it, NAS doesn't. But, according to those in the industry, progress is being made to develop a standard protocol for transmitting block-level storage over IP networks. That may mean some big changes ahead.
Indeed, according to Brent Ross, director of product marketing within the storage networking group at Adaptec (a company championing the technology), there will probably be half-a-dozen, so-called "iSCSI" product rollouts by various vendors by the first half of the year.
Here's the essence of what's at stake: NAS generally allows file-level data to be transmitted across existing IP networks. The basis of iSCSI tries to go beyond the capabilities of NAS by allowing the smaller grain, "block-level" data to be transmitted across an IP network.
Different vendors are taking various routes to achieve this. In concert with the standards issue, there are different technology approaches. One approach utilizes native IP SANs for transmitting storage data. Another approach tunnels SCSI or Fibre Channel over IP -- from one Fibre Channel SAN to another.
"The maturing of SAN technology in general and the delivery of Gigabit Ethernet in particular has made this a compelling proposition," says Ross.
James Opfer, principal analyst for server storage and RAID at San Jose, Calif.-based Dataquest, agrees that there is a need for moving block-level data over longer distances. "Adaptec is one of the companies that has been active in driving standards and understands the interaction they can have with the technology," he says.
"One of their goals seems to be to make this kind of block-level storage easier to implement and manage and there's reason to believe they will be successful," adds Opfer.
To his credit, Adaptec's Ross also notes that other companies -- including IBM and Cisco -- are also taking leadership roles in helping to define these standards and technologies. According to Peter Aylaian, director of product marketing at Adaptec, "This standard is coalescing very rapidly compared to most because so much of the [IP] infrastructure is already in place -- it's a tremendous incentive."
About the author: Alan Earls is a freelance writer in Franklin, Mass.
