1. A method comprising: temporarily storing, by a network storage controller, write data associated with a conventional data write request on a temporary memory in the network storage controller, wherein the conventional data write request is initiated by a remote client device, and the conventional data write is one of a Network File System (NFS) request or a Common Internet File System (CIFS) request; generating, by the network storage controller, a scatter-gather list associated with the data write request; and converting, by the network storage controller, the conventional client-initiated data write request into a compound remote direct memory access (RDMA) operation including the scatter-gather list, an independent data write operation, and various independent metadata operations, wherein, when initiated by the network storage controller, the RDMA operation transfers data over a serial interface from the temporary memory to an external non-volatile solid-state memory (NVSSM) subsystem according to the scatter-gather list, and wherein the scatter-gather list indicates multiple source memory locations in the temporary memory associated with the data write request and multiple corresponding destination memory locations in the NVSSM subsystem, the multiple destination memory locations including a memory location for the write data and a first type of metadata on a first type of memory of the NVSSM subsystem and a memory location for a second type of metadata on a second type of memory of the NVSSM subsystem, and wherein the first type of metadata is different than the second type of metadata and the first type of memory is different than the second type of memory.