Network File System (NFS)

• The NFS protocol is designed to be portable across different machines, operating systems, network architectures, and transport protocols - pportability is achieved through the use of Remote Procedure Call (RPC - see RFC 1057) primitives built on top of an eXternal Data Representation (XDR - see RFC 1014).
• Network File System (NFS) is file system that will mount remote file systems across homogenous and heterogenous systems.
• NFS consists of a client and server systems - the server can export local directories for remote clients to use.
• The supporting mount protocol allows the server to hand out remote access privileges to a restricted set of clients.  It performs the operating system-specific functions that allow, for example, to attach remote directory trees to some local file system.
• All of the procedures in the NFS protocol are assumed to be synchronous.  When a procedure returns to the client, the client can assume that the operation has completed and any data associated with the request is now on stable storage.
• NFS runs over IP using UDP (commonly)  - there are implementations that will work using TCP as the network transport service.
• NFS was originally developed by Sun Microsystems Computer Corp. (SMCC) and is now part of their Open Network Computing (ONC) initiative.
• NFS has been accepted by the IETF in certain RFC's (1094) as a standard for file services on TCP/IP networks on the Internet.

• NFSPROC_GETATTR(fhandle)
• NFSPROC_SETATTR(sattrargs)
• NFSPROC_ROOT(void)
• NFSPROC_LOOKUP(diropargs)
• NFSPROC_READLINK(fhandle)
• NFSPROC_READ(readargs)
• NFSPROC_WRITECACHE(void)
• NFSPROC_WRITE(writeargs)
• NFSPROC_CREATE(createargs)
• NFSPROC_REMOVE(diropargs)
• NFSPROC_RENAME(renameargs)
• NFSPROC_LINK(linkargs)
• NFSPROC_SYMLINK(symlinkargs)
• NFSPROC_MKDIR(createargs)
• NFSPROC_RMDIR(diropargs)
• NFSPROC_READDIR(readdirargs)
• NFSPROC_READDIR(readdirargs)

Basic Data Types

• fhandle - The type "fhandle" is the file handle that the server passes to the client.  All file operations are done using file handles to refer to a file or directory.  The file handle can contain whatever information the server needs to distinguish an individual file.
• fhstatus - The type "fhstatus" is a union.  If a "status" of zero is returned, the call completed successfully, and a file handle for the "directory" follows.  A non-zero status indicates some sort of error.
• dirpath - The type "dirpath" is a server pathname of a directory.
• name - The type "name" is an arbitrary string used for various names.

• MOUNTPROC_NULL(void)
• MOUNTPROC_DUMP(void)
• MOUNTPROC_UMNT(dirpath)
• MOUNTPROC_UMNTALL(void)
• MOUNTPROC_EXPORT(void)