NFS version 4 has features that are not available in the previous versions.
To map these version 4 ID strings to a local numeric ID
To map the local numeric IDs to version 4 ID strings
For more information, refer to nfsmapid Daemon.
Note that in NFS version 4, the ID mapper, nfsmapid, is used to map user or group IDs in ACL entries on a server to user or group IDs in ACL entries on a client. The reverse is also true. For more information, see ACLs and nfsmapid in NFS Version 4.
With NFS version 4, when you unshare a file system, all the state for any open files or file locks in that file system is destroyed. In NFS version 3 the server maintained any locks that the clients had obtained before the file system was unshared. For more information, refer to Unsharing and Resharing a File System in NFS Version 4.
NFS version 4 servers use a pseudo file system to provide clients with access to exported objects on the server. Prior to NFS version 4 a pseudo file system did not exist. For more information, refer to File-System Namespace in NFS Version 4.
In NFS version 2 and version 3 the server returned persistent file handles. NFS version 4 supports volatile file handles. For more information, refer to Volatile File Handles in NFS Version 4.
Delegation, a technique by which the server delegates the management of a file to a client, is supported on both the client and the server. For example, the server could grant either a read delegation or a write delegation to a client. For more information, refer to Delegation in NFS Version 4.
Starting in the Solaris 10 release, NFS version 4 does not support the LIPKEY/SPKM security flavor.
Also, NFS version 4 does not use the following daemons:
For a complete list of the features in NFS version 4, refer to Features in NFS Version 4.
For procedural information that is related to using NFS version 4, refer to Setting Up NFS Services.