Addressed is a system and method for remote data caching and replication
by local copy maintenance of remote data within a SAN file system.
Distributed Storage Tank (DST), an extension to a SAN file system,
provides for transparent SAN client access of local copies by importing,
exporting, and storing data using network file access protocols as well
as by providing assurance of metadata and file content validity. A Remote
Access Agent (RAA) handles protocol implementation and conversion
necessary for communication with remote data sources. Controlled by a
consistency policy, consistency is maintained by RAA fetching and
updating local copies if modifications have occurred to a file since it
was first stored as a local copy in local storage. Additionally, RAA
returns metadata pertaining to the requested data. A SAN client obtains
metadata corresponding to the requested data and utilizes it to directly
access locally stored copies of remote data.