Method and apparatus for a caching file server

Abstract

A method and apparatus are described for a caching file server ('CFS') system which permits end user client programs on a local node of a distributed computer system, to issue requests to read/write data to a remote file and to query/set attributes of the remote file, and to have these requests serviced by the CFS in a way which minimizes the caching resources used as well as minimizes the related network communications. The CFS establishes CFS file programs to interface with the client programs, and sets up a common CFS cache for the file attributes, which cache is kept current via a communications link to a file program in a file server at the remote node containing the file, wherein the file program automatically updates the common CFS cache whenever any attributes change. The CFS also caches the results of bind operations in order to further minimize network calls and redundant cache usage. In addition the CFS coordinates all client program requests for read/write data requests with a virtual memory manager ('VMM') on the local node, servicing all client programs from a single pager program in the VMM which is coupled to a cache program in the file server of the remote node. VMM page-in/page-out operations go directly to the remote file server without CFS intervention. In this manner, network communications and related processing overhead as well as memory resources may be minimized by use of the VMM for caching file data and the Common CFS cache for caching file attributes.