Rob I agree with you, as I have been working only with 10GB CNA's Intel X520's I was not quite aware of the possibility of FCoE working with less speed adapters as well, hence posted the question. I am pretty sure, we will see their own problems dealing with slow adapters, but for now we are sticking to 10GB CNAs from Intel for our testing.
Non the less, thanks for your detailed explanation, appreciate that. Thanks, Prasad ----- Original Message ----- From: "Robert Love" <[email protected]> To: "Prasad Gondi" <[email protected]> Cc: [email protected] Sent: Monday, January 13, 2014 3:17:25 PM Subject: Re: [Open-FCoE] Does FC-BB-6 VN2VN work with 1 Gb (not 10 GbE) Network Adapters and Switches? On 01/13/2014 02:29 PM, Prasad Gondi wrote: > Rob > > Can we do this over 1GB nic also? could you please provide some details over > which 1GB nics are supported FCoE typically goes hand-in-hand with "converged networking," which basically means DCB. The idea being that you split your Ethernet pipe into different classifications. This allows you to do FCoE on the same Ethernet link that you're doing other non-storage traffic on. FCoE uses DCB's PFC (Priority Flow Control) to provide lossless Ethernet to transmit on. Keep in mind that with iSCSI you have the reliability of TCP/IP, but with FCoE you don't have that support. When sending FCoE packets over 1Gb/s you're not going to be using DCB or PFC, so you'll just be using traditional (pause) flow control. This is fine as long as you're not doing converged networking. So, as long as you don't bog down your pipe with other traffic that would that would cause excessive PAUSE frames, thus impacting your FCoE traffic, I think you should be fine. I do not think that the impact of converged networking over 1Gb/s has really been studied much. DCB and and other FCoE offloads, such as Intel's Direct Data Placement feature are only implemented in 10Gb/s HW. I am sure this FCoE/DCB feature availability only being available in 10Gb/s NICs is true for any vendors selling FCoE/DCB cards. Some vendors may not provide DCB support or offloads at all. The industry is focused on 10Gb/s. You can do FCoE on 1Gb/s, but it's not the norm and nobody is testing it. The way the kernel is coded any Ethernet adapter should be able to do FCoE. I am unaware of any 'supported adapters' list and would seriously doubt that you'd find any 1Gb/s card data sheet even mentioning FCoE/DCB. Hope this helps, //Rob _______________________________________________ fcoe-devel mailing list [email protected] http://lists.open-fcoe.org/mailman/listinfo/fcoe-devel
