HP-UX 11i Release Notes (December 2000)

ManualsBrandsHP ManualsSoftwareHP-UX 11i v1.6 Technical Computing (TCOE) LTU

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New and Changed Disk and File Management Features

Network File System Support for TCP/IP (new)

Chapter 9178

Network File System Support for TCP/IP

(new)

Network File System (NFS) is now supported over the

connection-oriented protocol, TCP/IP for NFS versions 2 and 3, in

addition to running over User Datagram Protocol (UDP). TCP transport

increases dependability on wide-area networks (WANs). Generally,

packets are successfully delivered more consistently because TCP

provides congestion control and error recovery.

As a result, with this new functionality, NFS is now supported over

WANs. As long as TCP is supported on the WAN, then NFS is supported

also.

The mount_nfs commandnow supports a proto= optionon the command

line where the value for proto can be either UDP or TCP. (In the past,

this option was ignored.) This change allows the administrator to specify

which transport protocol they wish to use when mounting a remote ﬁle

system.

If the proto= option is not speciﬁed, by default, NFS will attempt a TCP

connection. If that fails, it will then try a UDP connection. Thus, by

default, you will begin using TCP instead of UDP for NFS trafﬁc when

you begin using the 11i version of HP-UX. This should have little impact

you. You do, however, have the option to specify either UDP or TCP

connections.

If you specify a proto= option, only the speciﬁed protocol will be

attempted. If the server does not support the speciﬁed protocol, the

mount will fail.

nfsd now opens TCP transport endpoints to receive incoming TCP

requests. For TCP, the nfsd is multi-threaded. For UDP, the nfsd is still

multi-processed.

Kernel TCP threads execute under the process nfskdtcp. When counting

the number of nfsd processes, keep in mind the following algorithm: An

equal number of nfsd's that support UDP will be created per processor

and only one nfsd that supports TCP will be created. In the case of a

four-way machine and NUM_NFSDS=14 (set in

/etc/rc.config.d/nfsconf), 17 nfsd’s will be created: 16 for UDP (4

per processor) and 1 for TCP.