NFS Services Administrator's Guide

Configuring and Administering NFS
NFS Client and Server Transport Connections
Chapter 2 59
If TCP is not available on the server, the mount fails.
You can tell NFS to use ONLY UDP by using the following command:
mount -o proto=udp
If UDP is not available on the server, the mount fails.
NFS Server Transport Connections
On the NFS server, to ensure a request for a TCP connection will be
successful, the service must be advertised in the /etc/services name
database file. This database advertises the availability of TCP on the
server through port 2049. The entry appears in the /etc/services
name database file. There is also an entry for UDP. They are as follows:
nfsd 2049/tcp #NFS remote file system
nfsd 2049/udp #NFS remote file system
NOTE Note that these entries are automatically added to the /etc/services
file since this service must be advertised in order to start the server
daemon (nfsd) correctly. Be sure that the local map resolution points to
the local file. If NIS maps are used, be sure that the services file used by
NIS also contains this additional entry for TCP.
Changes to the NFS Server Daemon (nfsd)
The NFS server daemons (nfsd) handle client file system requests. For
NFS over UDP transport, the default number of nfsd processes is
defined by the NUM_NFSD variable in the /etc/rc.config.d/nfsconf
file. This default number of nfsd processes over UDP is a suggested
number for the HP-UX kernel. At the system boot time, the kernel reads
this default number and it automatically rounds up the number of NFS
server daemons (nfsds) to be a multiple of the number of active CPUs in
the system. For NFS over TCP transport, only one additional nfsd
daemon is started to service TCP requests.
NOTE For the HP-UX release 11.0, the default number of nfsd processes
running on an NFS server is 8 nfsd processes over UDP transport. This
default number is defined by the NUM_NFSD variable in the
/etc/rc.config.d/nfsconf file.