Enabling iSCSI Migration

The future of Internet SCSI (iSCSI) has been the subject of rampant speculation in the storage industry for the past two years. While iSCSI represents the ultimate convergence of SANs with mainstream TCP/IP networking, some early market products failed to establish sufficient end-user value to gain market acceptance. IBM's recent withdrawal from the market of its iSCSI-based 200i TotalStorage array and Cisco's lack of success with the NuSpeed SN 5420 switch have fostered an industry attitude that iSCSI may not be ready for prime time. At the same time, however, the iSCSI standards process is nearly complete, new wire-speed iSCSI host adapters and IP storage switches from other vendors are now available, and Microsoft has announced support for iSCSI in its forthcoming .NET operating system. These mixed iSCSI messages may be confusing the industry and customers alike, but perhaps the problem is not with iSCSI itself, but how individual vendors have marketed the technology.

Some of the early vendor marketing collateral on iSCSI positioned the technology as a viable solution only for low end storage applications. Running an iSCSI device driver on laptop PCs, for example, would enable laptops to perform block data backup over standard Ethernet networks. In part, this market positioning for the low end was based on the very limited performance of some products. Vendors with wire-speed products, by contrast, have been positioning iSCSI as a solution for data center and high performance storage applications. The fact is there is nothing inherently limiting in the iSCSI protocol that would restrict it to low level or higher end applications. As with TCP/IP networking in general, customers get what they pay for, and those willing to pay more can get more in terms of functionality and performance.

The introduction of high performance iSCSI host adapters at a list price of between $600 and $1000 challenges the vendor hype that iSCSI is much cheaper than Fibre Channel. While iSCSI adapters are somewhat more economical than comparable Fibre Channel HBAs ($1200 $2000 price range), they are still much more expensive than standard Gigabit Ethernet NICs ($100 $500 price range). The real savings for customers, then, is not in hardware acquisition costs, but in leveraging the IP infrastructure, expertise and network management tools already in place in their corporate networks.

Although enterprise-class iSCSI storage arrays are not expected to appear in the market until 2003, the availability of iSCSI host adapters and wire-speed IP storage switches will radically change the composition of SANs through the remainder of this year. Why? Because customers will now have the flexibility to deploy servers anywhere in the IP network instead of tethering servers to dedicated Fibre Channel switches. With the ability to now use more of their familiar IP infrastructure and support staff to implement SAN solutions, customers can expand their storage networking applications without simultaneously hiring more Fibre Channel fabric experts. Finally, when iSCSI storage systems come to market, customers can simply integrate them into their existing IP SAN, side by side with Fibre Channel arrays and hosts that have already been brought into the IP SAN via IP storage switches. As shown by Carlson Companies and other customers, implementing IP-based storage networks is viable today, even as new IP storage products continue to be introduced to the market.

This heterogeneous iSCSI migration enables customers to select the best-in-class Fibre Channel storage and iSCSI adapter products without being locked into a specific technology solution. Customers can thus set their own pace for integrating IP and Fibre Channel products while taking full advantage of the functionality and performance offered by both.