The “not owner” error is displayed on the client system (usually Solaris) when attempting to mount an NFS share from a server. This error may appear even though the share is correctly exported and the client system has full access. If you are getting a “permission denied” error, then this article is not for you and you should check here instead.

The “not owner” error is likely when the server is running NFS v. 4 and the client is running NFS v. 3 or an earlier release of v. 4. This error sometimes also appears when the NFS server is a Linux system and the client system is running Solaris.

To resolve the problem:

1. edit /etc/default/nfs (this location is for Solaris; for other operating environments just do a search for a file called “nfs” in /etc) on the client system
2. modify or add the following line: NFS_CLIENT_VERSMAX=3
3. save the file and attempt to mount the share again. You do not need to restart NFS. You may need to restart automounter, if that is what you are using.

The above change will force the client to use NFS v. 3, which at the moment is more widely-compatible than version four. This should not cause any problems for the NFS server or other clients.