NFS program unregistered

[David Nixon]

NFS mount requests to an 11.11 NFS server began to fail.. This NFS service had been up and running for several weeks

Investigation with 'rpcinfo' revealed that the UDP and TCP nfs programs were no longer registered with 'rpcbind': Starting some additional 'nfsd' processes re-registered the UDP program and client mounts could then proceed.

What circumstances might cause a running 'rpcbind'
to "forget" about a previously registered program?

I'm running ONC patch level PHNE_34293.

[Sundar_7]

If rpcbind is killed and restarted without the -w option, you will need again restart the NFS daemons, so they will again register with the RPC server daemon (i.e rpcbind).

[David Nixon]

To clarify: my 'rpcbind' process has not been
killed and restarted..

[Peter Nikitka]

Hi,

this should not happen automatically. It is possible to drop rpc services manually quite easy, though. The owner (who can do this) of the nfs service is root, so the number of people should be very limited:

rpcinfo -d service version

Shutting down the nfs via the rc-script should have the same effect.

Check if someone 'optimized' nfsd requests or tried to shutdown NFS.

mfG Peter

[David Nixon]

Well there weren't any attempts to shutdown NFS,
so 'rpcinfo' -d seems to be the only other sanctioned
mechanism for un-registering the nfs
programs - though I couldn't find instances of such usage
in relation to my reported incident.

Attempts to remotely unregister programs;
using a forged 'pmap_unset' UDP packet, failed.

[David Nixon]

I have been unable to determine the source
of the unregister nfs request to 'rpcbind'.