FCoE is possible between two Data Centres by using VE ports to build multi-hop FCoE fabrics that interconnecting FCF, the VE port functions as a FC E-port on top of a lossless ethernet fabric.
The maximum distance between two Cisco Nexus 5000 Series switches is 3000m for FCoE (lossless Ethernet) traffic with NX-OS 5.0(2)N1.1. It can be enabled using the pause no-drop buffer-size buffer-size pause-thresholdxoff-size resume-threshold xon-size command in QOS configuration. Here are the maximum distances:
Nexus 55xx to Nexus 55xx – 3km
Nexus 50×0 to Nexus 50×0 – 3km
Nexus 50×0 to Nexus 55xx – 3km
Nexus 55xx to Nexus 2232 – 300m
Nexus 50×0 to Nexus 2232 – 300m
Current customers with fibre channel environments looking to refresh their infrastructue always ask me one question, can we replace fibre channel with FCoE end to end for my whole environment.
For most customers, 100% virtualisation is a dream that wont be happening in the near future, replacing fibre channel with FCoE is in the same boat.
Unfortately unless you are replacing all of your compute, storage and connectivity end to end FCoE is simply not possible and if you have non-virtualised workloads its even further away!
I have vendors consistently telling me they have customers going 100% FCoE only to find it a small environment where the requirements are specific enough to make FCoE end to end happen.
Unfortunately we are at the stage where hype/vendors/expectations dont meet expectations and that lands us fair and square in the trough of disillusionment.
Recently I attended Cisco’s brisbane partner update of their UCS product. There have been some changes since UCS was first released about 19 months ago (ANZ). I went to the first partner briefing in Sydney early last year and the primary take away was that the Fabric extenders, the 6400’s could only connect to a Nexus product like the 5K or 7K switches. This was due to the Fabric operating native FCoE requiring FCoE aware infrastructure. This meant that customers without 5K or 7K switches were required to also invest in this technology at the same time or prior to moving to UCS.
Its great that Cisco has changed its stance on this with a software release in April using NPIV. Also in smaller environments you can now directly connect FC front end ports of storage to the 6100 Fabric interconnect.