This feature is new in the Software Express pilot program. In the Solaris Express 8/04 release, NFS version 4 became the default. This feature is included in the Solaris 10 3/05 release.
The Solaris 10 OS includes the Sun implementation of the NFS version 4 distributed file access protocol. This version is the next logical step in the evolution of NFS. The NFS version 4 protocol, specified in RFC 3530, was created under the auspices of the Internet Engineering Task Force (IETF). This version is designed to be both vendor neutral and operating system neutral.
NFS version 4 integrates file access, file locking, and mount protocols into a single, unified protocol to ease traversal through a firewall and improve security. The Solaris implementation of NFS version 4 is fully integrated with Kerberos V5, also known as SEAM, thus providing authentication, integrity, and privacy. NFS version 4 also enables the negotiation of security flavors to be used between the client and the server. With NFS version 4, a server can offer different security flavors for different file systems.
The Solaris implementation of NFS version 4 includes delegation, a technique by which the server can delegate the management of a file to a client. This technique can reduce the number of round-trip operations because the client is guaranteed that no modification can occur without the server informing the client. The protocol also includes operation compounding, which allows multiple operations to be combined into a single “over-the-wire” request.
For more information about NFS version 4, refer to Chapter 6, “Accessing Network File Systems (Reference),” in the System Administration Guide: Network Services.