As with other network services, problems can occur on machines that use the Network File System (NFS). Troubleshooting for these problems involves understanding the strategies for tracking NFS problems, recognizing NFS-related error messages, and selecting the appropriate solutions. When tracking down an NFS problem, isolate each of the three main points of failure to determine which is not working: the server, the client, or the network itself.

Discussion thread on NFS failures similar to ours.  Indication is to use tcp rather than udp as the transport for nfs.

Solaris has a slightly different format on the server end from other operating systems. Instead of /etc/exports, the configuration file is /etc/dfs/dfstab. Entries are of the form of a share command, where the syntax for the example in Section 3 would look like

share -o rw=slave1,slave2 -d "Master Usr" /usr

and instead of running exportfs after editing, you run shareall.

Solaris servers are especially sensitive to packet size. If you are using a Linux client with a Solaris server, be sure to set rsize and wsize to 32768 at mount time.

Many supposed NFS problems are really problems with the firewall. In order for your NFS server to successfully serve NFS shares, its firewall must enable the following:

• ICMP Type 3 packets
• Port 111, the Portmap daemon
• Port 2049, NFS
• The port(s) assigned to the mountd daemon