This information is partly taken from Nicolai Langfeldt's excellent NFS HOWTO, and is current as of 10/1/1999.
Most version 2.2.x kernels need a set of patches to install the knfsd subsystem, maintained by H.J. Lu, to communicate efficiently (if at all) with Sparc, IBM RS, and Alpha machines, and probably others. This package is actually a collection of patches to the kernel sources. Better support for non-Intel architectures is included in the 2.4 kernels.
There is also a user-space server. Although it lacks remote file locking, it is easier to install. It may be equally efficient.
In the Documentation/Changes of recent kernel distributions, there is a list of URL's for both the knfsd server and the user-space server.
There is a CVS server available for the kernel-space NFS subsystem, as well as a NFS WWW page at http://www.linuxnfs.sourceforge.org/, although the URL requires a password for access. The relevant URL's are listed in the README.nfs file at ftp://ftp.us.kernel.org/, and other kernel archive sites, along
with login information. Patches are at ftp://ftp.varesearch.com/pub/kernel/latest/patches/.
The source archives of the user-space server and utilities currently reside on ftp://linux.mathematik.tu-darmstadt.de:/pub/linux/people/okir/.
In the case of older Solaris releases, the lack of statd or lockd on a client or server machine may cause incompatibility. On some versions of Solaris, statd can be used to exploit features of the automounter. Sun released a patch to correct this, but statd still needs to be started by root on such systems. On recent Solaris systems, refer to the information in
/etc/dfs/dfstab and the share(1M) manual page to enable volume sharing. In addition, the rpcinfo program can tell you if statd or lockd are available on the local or remote machines.
The linux-kernel mailing list has on-and-off discussions of the status of the NFS subsystem, which appears to be changing rapidly.
[Nicolai Langfeldt, Robert Kiesling, Anders Hammarquist]