Key reuse for RDMA virtual address space

A system and method for reusing an R_Key associated with InfiniBand virtual address space mapped to local, host, storage. An R_Key is initially assigned by an HCA (Host Channel Adapter) when a host registers a set of local storage buffers. The HCA maps the local buffers to virtual address space and returns the R_Key. When the host augments the mapped local storage by identifying additional buffers, the HCA maps the larger storage area to virtual address space and returns the same R_Key. When the host removes local storage from the mapping scheme, the HCA returns a smaller virtual address space associated with the same R_Key.