InfiniBand, iWARP, RoCE
In the HPC world InfiniBand became the most prominent interconnect solution about 2014. It is proven technology, and with iWARP and RoCE it bridges into the Ethernet world as well.
It brings the right properties for a storage networking solution. It offers bandwidth ahead of the curve, it has lower latency. It comes with an advanced API: RDMA/verbs.
The DRBD RDMA Transport allows you to take advantages of the RDMA technology for mirroring data in your DRBD setup. With it DRBD supports multiple paths for bandwidth aggregation and link failover.