What are the advantages of using FCoE to expand SAN?
One of the main benefits is network consolidation using 10GbE Ethernet. The ubiquity and increased bandwidth capability of 10GbE can eliminate the need for a separate physical network infrastructure for storage network traffic, helps to save infrastructure costs and is an option for data center custiomers of any size. For NetApp FCoE is a logical progress of NetApp’s unified storage approach of offering FC, iSCSI and NAS in its enterprise systems, and provides an evolutionary path for Fibre Channel SAN customers to migrate over time. NetApp ist still the only provider to offer native FCoE support for its storage systems.
Is it an alternative to iSCSI?
FCoE is an addition to iSCSI rather than an alternative as the 10GbE will rule the network world. One shouldn’t forget that iSCSI will remain the only block-oriented protocol for 1Gb Ethernet for still some time. So it will benefit from the improved performance on the network. iSCSI networks benefit from shortest path bridging to reduce unnecessary hops along the data path. As network devices learn the shortest paths from node to node, all traffic benefits from more efficient data paths.
Do you think the traditional Ethernet have the required characteristics to handle FC traffic?
Today Ethernet is a best-effort network that may drop packets or deliver packets out of order when the network is busy. The results are retransmissions and time-outs—something that is not acceptable for a storage network. To create a new, more capable family of Ethernet protocols new standards are being developed. These standards, referred to collectively as Converged Enhanced Ethernet (CEE), will enable lossless Ethernet fabrics. Lossless Ethernet extensions such as PFC, ETS, bridging, and congestion notification enable a 10Gb Ethernet connection to support multiple traffic types simultaneously, preserving their respective traffic properties. With these extensions, the same 10Gb Ethernet link can enhance iSCSI performance and robustness and also be able to support Fibre Channel storage traffic by offering a no-drop capable consolidated I/O fabric.