1. A method of emulating a remote direct memory access (‘RDMA’) link between controllers in a storage array, the method comprising: inserting, into a buffer utilized by a direct memory access (‘DMA’) engine of a first storage array controller, a data transfer descriptor describing data stored in memory of the first storage array controller and a location to write the data to memory of a second storage array controller; retrieving, in dependence upon the data transfer descriptor, the data stored in memory of the first storage array controller; writing the data into the memory of the second storage array controller in dependence upon the data transfer descriptor; and signaling that the data transfer descriptor has been processed.