1, 2, 4, 8, 10: The Evolution of Fibre Channel
1, 2, 4, 8, 10: Those numbers aren't some high school football cheer, but Fibre Channel options facing users over the last five years and into the future. These are technology choices that we will have to make, and it might be a good idea to explore the various technologies, the implications of using them, and the decisions we are going to have to make over the next few years. There are a few issues to consider as we explore these issues:
- Storage performance has not changed much, and disk density has become a performance issue, since the long-term trend has been toward less bandwidth per GB of storage.
- 10 Gb per second Fibre Channel sites are going to have to change infrastructure to support the 10 Gb standard.
- Going from 1Gb/s to 2Gb/s Fibre Channel, and even 4 Gb, 8 Gb and 10 Gb, might not improve your performance if you are only making small I/O requests.
The Fibre Channel of just a few years ago is changing. Arbitrated loop devices are becoming a thing of the past. New tape, disks and RAIDs made by vendors now support full fabric devices. Those 1 Gb devices are a thing of the past, and in the not too distance future they will be gone. Everything becomes obsolete in our industry, but the length of time it takes varies depending on the requirements of the major stake holders of that technology, the time it takes to get a new technology to market, and the impact that new technology has on the market.
1 Gb FC arbitrated loop had some but not a lot of impact on the market. It was only three times faster than the other standard technology of the time, Ultra-SCSI. It was not on the market for very long before it was superseded by 1 Gb fabric technology, and the number of products and the competition for the early adopters of this technology was not great.
1 Gb full fabric was not well adopted compared with 2 Gb technology, since it was not on the market that long either. We have been living with 2 Gb technologies for about three years now, which is far longer than either of the 1 Gb technologies lasted before they were superseded.
We are now on the verge of 4 Gb technology with RAID controllers and switches, since we already have 4 Gb HBAs, and much of the technology that allows for 4 Gb will allow for 8 Gb. That means you will be able to plug 8 Gb technology into the RAID controllers and switches that support 4 Gb. It does not mean that all of them will support 8 Gb, but it does mean that you do not need a complete infrastructure change to move from 4 Gb to 8 Gb. This is unusual for our industry, but it did happen with 1 Gb to 2 Gb technology.