Open-source efforts for RDMA

Several open-source efforts for enabling RDMA services on Linux have recently been initiated.

OpenRDMA starts from RNICPI, a transport-neutral and openly accessible specification supported by several iWARP RNIC vendors, and favors a layered architecture with a clean separation between generic and verbs-provider-specific functionality.

OpenIB was originally focused on InfiniBand and has recently announced its intent to also support iWARP by forming the OpenFabrics alliance. OpenIB maintains the InfiniBand driver component in the mainline Linux kernel.

OpenFabrics is the successor of OpenIB and develops transport agnostic open-source software for RDMA fabric technologies. Founded in June 2004 as the OpenIB Alliance to develop a Linux-based InfiniBand software stack, the organization has expanded its charter to support iWARP (RDMA over Ethernet).

Despite the competition between these still young open-source efforts, we assume that the Linux support for iWARP and InfiniBand-based RDMA will evolve and converge mostly based on performance considerations.