UNFS3 (User-Space NFSv3 Server)
(C) 2003-2006, Pascal Schmidt <unfs3-server@ewetel.net>


INTRODUCTION
============

UNFS3 is a user-space implementation of the NFSv3 server
specification.

UNFS3 supports all NFSv3 procedures with the exception of the
READDIRPLUS procedure. It tries to provide as much information
to NFS clients as possible, within the limits possible from
user-space.

See the unfsd(8) manpage for restrictions imposed on NFS
operations (section RESTRICTIONS) and for possible races
with local file system activity (section BUGS).

It is not possible to export to netgroups or wildcard hostnames
via /etc/exports, all other addressing methods should work. The
following options are recognized in the exports file: ro, rw,
root_squash, all_squash, no_root_squash, no_all_squash. If
other options are present, they are ignored.

Cluster extensions compatible to the older ClusterNFS project
are supported when the source is configured with --enable-cluster.


SUPPORTED SYSTEMS
=================

Linux:		compiles and runs, passes Connectathon 2003 NFS
		testsuite's "basic" and "general" tests, survives
		fsx stress testing

Solaris: 	compiles and runs, survives light testing

NetBSD: 	compiles and runs, but there are compatibility
		problems with the in-kernel NFS client

AIX:		compiles

Irix:		compiles (with gcc and native compiler)

OS X:		compiles

Note that only Linux support is checked for all releases. If unfs3
breaks on other platforms, a bug report is appreciated.


INSTALLATION
============

You will need gcc, lex (flex), and yacc (bison) to compile UNFS3.

	./configure
	make
	make install

Please read the manpage for information about command-line
options.

	man 8 unfsd

If you decide to modify the code yourself, you can run

	make dep

to append dependency information to the Makefile, so that make
knows which files depend on each other and recompiles all the
necessary files on changes.


CVS REPOSITORY
==============

The unfs3 CVS repository is accessible via anonymous CVS. The source
can be checked out with:

  cvs -d:pserver:anonymous@cvs.lysator.liu.se:/cvsroot/unfs3 login
  cvs -d:pserver:anonymous@cvs.lysator.liu.se:/cvsroot/unfs3 co unfs3

You can also use the web-based CVS repository viewer at:

  http://cvs.lysator.liu.se/viewcvs/viewcvs.cgi/?cvsroot=unfs3

In the HEAD branch, you will find a file called "BRANCHES", which
describes the different branches in this repository.

Using UNFS3 for Linux nfsroot
=============================

General information about Linux nfsroot can be found in the
Linux kernel source, in the file Documentation/nfsroot.txt.

If you want the use the Linux kernel's "nfsroot=" boot option
to use a root directory on an NFS server and use UNFS3 in the
role of the NFS server for that, you need to remember that UNFS3
only supports NFSv3, not NFSv2. The kernel, on the other hand,
always defaults to using NFSv2. Thus, you need to modify the
nfsroot boot option to force the kernel to use NFSv3. If you do
not do this, an error message like this will appear on the
client machine:

  Looking up port of RPC 1000003/2 on 172.16.100.100
  Root-NFS: Portmapper on server returned 2049 as nfsd port
  Looking up port of RPC 1000005/1 on 172.16.100.100
  Root-NFS: mounted port is 2049
  NFS:      nfs_mount (ac106464:/nfsroot)
  RPC: call_verify: programm 100003 version 2 unsupported by server
  nfs_get_root: getattr error = 5
  nfs_read_super: get root inode failed
  VFS: Unable to mount root fs via NFS trying floppy

To fix this problem, append the "v3" NFS option to the nfsroot
boot option. Assuming your NFS server's IP address is 192.168.2.72
and the path you need to mount is /tftpboot/nfsroot, the boot
option should look like this:

  nfsroot=192.168.2.72:/tftpboot/nfsroot,v3

You can add more options to the end, seperated by commas. If you
use DHCP to pass the NFS server configuration to the client, you
need to use a line like this in the /etc/dhcpd.conf settings
for the client machine:

  option root-path "/tftpboot/nfsroot,v3";

As above, more options can be added to the end, sepereated by
commas.

Thanks go to Jean Aumont <JeanAumont@videotron.ca> for suggesting
this bit of information to be documented.