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Prediction: Fast is not everything

By Scott Bradner

The IETF about finished the first set of the IP-storage standards. There are quite a few more documents to come but good progress is being made on them. You should start to see iSCSI and FCIP products on the market soon, for some definition of "soon". I think that this technology may become an almost perfect case study for Clayton Christensen to use in the next edition of his book "The Innovator's Dilemma" because it will so clearly show how hard it is for people already in a business to properly understand the important features of a disruptive technology. It is my prediction that (1) this technology will be very successful and (2) the main success will be is just the area that many of the professional storage people dismiss as uninteresting.

The idea behind the IETF's IP storage protocols is quite simple. Just encapsulate Small Computer Systems Interface (SCSI), used to connect small disk drives to PCs, and Fiber Channel (FC), used to connect big disks to big computers in data centers, into an IP-based transport protocol. See the IETF IP Storage Working Group web page for more information. (http://www.ietf.org/html.charters/ips-charter.html).

There were two areas that generated major angst in the early work of this working group. (Not to imply that the working group is now an angst-free zone but it's better than it was.) The first area was security. When the working group charter was approved it specifically required that all implementations of the IETF IP-storage protocols must include strong security (both for cryptographic data integrity and confidentiality). Users do not need to use them if they do not want to but the ability to turn these on must be present in the product before the vendor can say that their product meets the standard. Quite a few working group participants really did not like this requirement -- they figured that the main use of these protocols would be in a data center or some other area protected by a firewall. But once you put an application on IP there is no way for the application to be sure where it is being used, e.g., behind a firewall. This is a major feature of IP.

The second area is performance. A number of people in the working group and the analyst community are quite focused on making sure that the IP storage protocols can run very fast because disk drives are very fast these days. Who would want a slow drive? I expect that the implementations will be able to operate at high speed, for example, tests have shown that the Mac laptop I have can transfer data at over 450 Mbps (it has a built-in Gbps Ethernet), I would expect it will be able to run IP storage protocols at nearly that speed. But I think the biggest use for IP storage will because of the flexibility of IP and that performance is very much a secondary issue. In the Christensen book, slower smaller disk drives won the market over bigger faster ones. I think the same thing will happen here and that the vast majority of IP storage use will low-ish speed.

disclaimer: Harvard has had a long time to figure out how to do things slowly but this prediction of the importance of flexibility is my own.