Currently the twittersphere and blogosphere is actively discussing Fibre Channel over Ethernet (FCoE). The conversation was triggered by a post by Hu Yoshida from HDS, and I wanted to share my thoughts.
One of the most interesting responses was this one by Nigel Poulton where he explains the infrastructure required for FCoE. He goes into great detail highlighting the lossless nature of FCoE and the required hardware and cabling. The key takeaway is that FCoE is not iSCSI; it does not use generic 10 Gigabit Ethernet (10 GigE) hardware. You will need different cabling and advanced switches to meet the more stringent demands of FCoE.
The requirement for specialized FCoE hardware will increase costs versus iSCSI. iSCSI can leverage existing LAN investments and benefits from the economies of scale of Ethernet hardware. The specialized nature of FCoE means that it will ship in lower volumes than vanilla 10 GigE and thus it will take longer for FCoE hardware prices to decline. This will impact the ROI of FCoE solutions since the higher cost will extend the payback period. Thus, FCoE will be at a price disadvantage to iSCSI; however, I believe that the two technologies address different markets. FCoE mimics the reliability and consistency of Fibre Channel, but will also mimic the high price. iSCSI in contrast, runs on mainstream Ethernet infrastructures and will provide a more cost effective although less reliable and slower performing option.
A real world experience would be useful in clarifying my thoughts. I sold iSCSI solutions (EqualLogic, if you must ask) to small businesses in a previous job. The prospects were companies who wanted the benefit of a shared storage environment and had limited budgets and sophistication. They were excited about iSCSI because it provided the benefit of a SAN without the cost and complexity of Fibre Channel. In my opinion, these customers will continue to favor iSCSI over FCoE. However, I believe that the target FCoE customer is a larger environment that already has an FC SAN in place.
It will be interesting to see where the market moves from a backup perspective. iSCSI is less common in today’s Gigabit Ethernet data protection environments. As 10 GigE prices decrease, high performance iSCSI will become widely available. Will this drive penetration for iSCSI backup targets? It definitely could for smaller companies like the one described above. However, I believe that enterprises have a strong need for the performance and reliability of FC/FCoE and will favor these technologies over iSCSI in the datacenter.
Another question is whether companies will favor FCoE over FC. Given the newness of FCoE, I believe that it will take a few years before companies start seriously implementing FCoE in the core especially since most enterprises already have large investments in FC. FC speeds will also continue to increase and keep the technology competitive. Long-term, FCoE will co-exist in corporate datacenter infrastructures along with FC, and it will be interesting to see how companies divide their I/O workload between the two.