intel網卡系列及RDMA支持

起源，intel網卡中的SFP+是啥？

SFP+是光纖模塊，是一種可熱插拔的，獨立於通信協議的光學收發器。SFP+光纖模塊是SFP的升級。SFP+光纖模塊在以太網和1G、2G、4G光纖通道上SFP已經得到了廣泛應用。SFP+爲了適應更高的數據速率，設計了比SFP增強的電磁屏蔽與信號保護特性。

 intel 800系列開始支持RoCE協議。通過lspci | grep Eth查看網卡型號。所以一般使用RDMA的都選擇邁絡思IB網卡，示例也都以邁絡思和soft-rdma（和soft raid或lvm類似）爲例。

iWARP (Internet Wide-area RDMA Protocol) is a network protocol that implements Remote Direct Memory Access (RDMA) over IP networks.

RoCE v2 (RDMA over Converged Ethernet version 2) is a network protocol that implements Remote Direct Memory Access (RDMA) over an Ethernet network.

RDMA is a host-offload, host-bypass technology that enables a low-latency, high-throughput direct memory-to-memory data communication between applications over a network.

These Intel® Ethernet Adapters support iWARP:

• Intel® Ethernet Network Adapter X722-DA2
• Intel® Ethernet Network Adapter X722-DA4

These Intel® Ethernet Adapters support both iWARP and RoCE v2:

• Intel® Ethernet Network Adapter E810-CQDA1 for OCP 3.0
• Intel® Ethernet Network Adapter E810-CQDA2 for OCP 3.0
• Intel® Ethernet Network Adapter E810-CQDA2
• Intel® Ethernet Network Adapter E810-CQDA1
• Intel® Ethernet Network Adapter E810-CQDA1 for OCP
• Intel® Ethernet Network Adapter E810-2CQDA2
• Intel® Ethernet Network Adapter E810-XXVDA2 for OCP 3.0
• Intel® Ethernet Network Adapter E810-XXVDA4 for OCP 3.0
• Intel® Ethernet Network Adapter E810-XXVDA2
• Intel® Ethernet Network Adapter E810-XXVDA4

網卡也有很多優化的地方，可以參見https://developer.aliyun.com/article/1120756。

因特爾網卡指南：https://downloadmirror.intel.com/785819/Adapter_User_Guide_28.2.pdf