One survey of IT professionals released July 26 contends there is continued growth in the adoption of both older Fibre Channel and newer iSCSI Internet-based connections for storage networking at the expense of NAS. A second survey, released earlier, finds only flat adoption rates for both.
Respondents to a Xiotech-sponsored survey said they expect the use of iSCSI to increase from less than 5 percent of their storage infrastructure today to nearly 19 percent in two years.
Accordingly, Fibre Channel also is expected to increase from about 34 percent to 41 percent.
iSCSI (Internet Small Computer System Interface), an Internet protocol-based storage networking standard for linking data storage facilities, was developed by the IETF (Internet Engineering Task Force).
By carrying SCSI commands over IP networks, iSCSI is used to facilitate data transfers over intranets and to manage storage over long distances.
Fibre Channel is a gigabit-speed network technology that has become the standard connection type for storage area networks. Despite its name, Fibre Channel signaling can run on both twisted-pair copper wire and fiber optic cables.
The growth of both topologies will impact direct, server-attached storage, which will drop from nearly half of existing infrastructures today to less than a quarter in two years, according to the Xiotech surveys 110 respondents.
"Both Fibre Channel and iSCSI bring great benefits to the storage environments of many organizations," said Mike Stolz, vice president of marketing for Xiotech in Eden Prairie, Minn.
"Both are seen as superior to direct-attached storage, as well as network-attached storage, which this study suggests will remain a niche option."
Survey respondents ranked Fibre Channel higher than iSCSI on a number of attributes, a Xiotech spokesperson said.
For example, on a one-to-five scale—with five being highest—Fibre Channel scored 4.49 on performance versus 3.55 for iSCSI.
Fibre Channel scored 4.35 for reliability and 4.16 for security, versus 3.49 and 3.41 respectively for iSCSI.
However, iSCSI was rated better for initial cost (3.55 versus 2.52 for Fibre Channel), and roughly at parity with Fibre Channel for ongoing costs and ease of use.
Surprisingly, there were few differences between respondents from smaller companies and larger ones in terms of interest in Fibre Channel or iSCSI.
However, smaller companies expressed different priorities for technical attributes in making storage purchase decisions, with respondents from both midmarket and larger companies (500 or more employees) giving greater weight to tiered storage options and data replication than those from smaller companies.
Ease of use and upgradability were significant issues regardless of company size, the spokesperson said.
Dave DuPont, senior vice president of marketing and business development at iSCSI storage appliance maker SANRAD in San Mateo, Calif., said he wasnt surprised that use of the older-school Fibre Channel connectors is still growing at a substantial rate.
"By no means," DuPont told eWEEK. "[But] I do think iSCSI growth is understated. I believe the inherent advantages of SANs, combined with surging data storage capacity requirements, are driving growth across the entire product category."
Simplified storage management, higher availability and better capacity utilization are clear benefits of both FC and iSCSI SAN architectures, DuPont said.
"The demand is great enough to fuel growth in both," DuPont said.
"One should also note that the different architectures are aimed at different markets today. An FC SAN is really a storage solution for enterprise data center servers. iSCSI SANs are, at least today, storage for the 85 percent of the servers out there that are not in enterprise data centers.
"Because enterprise data center server storage requirements are growing, I expect FC SANs to grow. iSCSI SAN growth will be significantly greater because SMB and departmental server storage is a much less saturated market."
iSCSI SAN growth within the enterprise will continue to accelerate as customers gain experience with the technology and the evident benefits become more broadly understood, DuPont said.
Xiotech supports both iSCSI and Fibre Channel with its Magnitude 3D 3000 storage systems.
Xiotech, a provider of data storage and data discovery software, conducted the survey in May and June 2006.
Respondents represented a range of company sizes, from less than 100 employees to more than 5,000, and primarily represented mid-level IT titles. Responses were collected via both the Web and hard-copy survey forms.