NFS over TCP (only) not working

[abhijitgk]

hi,

I am not able to start nfsd over *only* TCP.

I've configured TCP option (NFS_TCP=1) in /etc/rc.config.d/nfsconf.

Iam able to start nfsd over *both* TCP and UDP.
And also *only* on UDP, using the -p switch of nfsd (/usr/sbin/nfsd -p udp).

BUT, trying to do a "nfsd -p tcp" to start nfsd over TCP *only* does NOT work :(

doing an rpcinfo show
----
100003 2 tcp 0.0.0.0.8.1 nfs superuser
100003 3 tcp 0.0.0.0.8.1 nfs superuser
----
meaning nfsd has bound to rpcbind.

But trying to do a null-proc to the nfsd using "rpcinfo -T tcp localhost nfs" gives following error:
-----
rpcinfo: RPC: Program unavailable
program 100003 version 0 is not available
-----
surprising. moreover iam *NOT* able to mount directories on client. Meaning, nfsd is not really functioning.

"ps -ea | grep -e nfs -e rpc" gives:
------
598 ? 1:20 rpcbind
603 ? 0:00 nfskd
3206 ? 3:11 nfsktcpd
21816 ? 0:00 nfsd
17017 ? 0:00 rpc.lockd
17015 ? 0:00 rpc.statd
21835 ? 0:00 rpc.mountd
------
so all components of nfs server *are* running!


WHAT's the problem then? iam i missing something here.

is this a know bug?
does "nfsd -p tcp" is known not to work? while "nfsd -p udp" does and so "nfsd" plain, which starts nfsd on *both* tcp and udp.

please advice. how do i start nfsd *only* on TCP.

my system config is:
-----
uname -m: HP-UX 9000/821
uname -r: B.11.11
lastest NFS patches installed:
PHCO_24777, 1.0, mountall cumulative patch.
PHNE_24035, 1.0, ONC/NFS General Release/Performance Patch
-----

thanks in advance,
Abhijit.

[Ravi_8]

Hi, abhijitqk
NFS uses UDP protocol not the TCP

[Marcin Mirkowski_1]

Hi,

Of course NFS can use TCP connections, but You should only activete this on the long distance between server and client. On the short distance UDP is more efficient.
As I know on HP the udp is always available, so You cannot stop this for the NFS service, but You can activate TCP by the flag, for example by setoncenv command.
By default, if You mount some resource, if TCP is available, it will be used. Only when TCP is disabled, UDP will be used.

BR,
Marcin

[Jeff Schussele]

Hi Abhijit,

Couple of things:
1) Make sure you add
nfsd 2049/tcp
to the /etc/services file as only the UDP entry is there by default.
2) Get the latest NFS performance patch PHNE_26388. Many TCP related problems have been addressed in these NFS perf patches since PHNE_24045

HTH,
Jeff