VMware, Inc.
Zero copy method that can span multiple address spaces for data path applications

Abstract:

A system and method for transferring data between a user space buffer in the address space of a user space process running on a virtual machine and a storage system are described. The user space buffer is represented as a file with a file descriptor. In the method, a file system proxy receives a request for I/O read or write from the user space process without copying data to be transferred. The file system proxy then sends the request to a file system server without copying data to be transferred. The file system server then requests that the storage system perform the requested I/O directly between the storage system and the user space buffer, the only transfer of data being between the storage system and the user space buffer.