1. A persistent caching system, the system comprising: a client, wherein the client is configured to: i) access at least a portion of a data through a network, and ii) access at least a portion of virtual memory blocks through RDMA using one or more exported addresses; and a caching server of a storage system, wherein the caching server includes the data and is configured to: i) store the data in a number of virtual memory blocks, each of the virtual memory blocks referring to an associated memory-mapped file in a file system of the caching server, ii) export addresses of the virtual memory blocks to the client, and iii) page one or more virtual memory blocks being accessed by the client through RDMA to and/or from memory-mapped files that are associated with the accessed virtual memory blocks.