There are four, common reasons for this. First, check that you do not have an
incomplete or marginal Ethernet connection. Follow these steps:
1) Are cables correctly seated on connectors?
2) Are cable in good condition physically? There should not be crimps or
bends in the cable.
3) Check that all cables attached; make sure that none has been accidently
disconnected.
A second reason is that the remote host from which you are mounting a file
partition may be down. Check with the administrator of the system. You will not
be able to mount any file system from that system until the remote host is up
and running.
A third reason is that the /etc/portmap daemon may not be running. Check this
by following these steps:
1) Enter the line:
ps -ef | grep portmap
The output displayed should look like this:
root 90 1 0 Apr 25 ? 0:04 /etc/portmap
The numbers in the output may differ on your system. If you do not receive
this output, do these steps:
1) Log onto the system as "root".
2) Enter the line:
grep portmap /etc/inittab
The output should look like this:
nfs0:2:wait:/etc/portmap
If it doesn't, edit the file /etc/inittab and modify it to look this way.
3) Shut the system down into single-user mode; run-level S.
4) Reboot the system into multi-user mode; run-level 2.
A fourth reason is that the /etc/portmap daemon on the remote host isn't
running. To check this, follow these steps:
1) Log onto the system as "root".
2) Enter the command
rpcinfo -p
followed by a space and the name of the hostname you wish to check. You
should get a list of registered program numbers. If you don't:
3) Shut the system down into single-user mode; run-level S.
4) Bring the system back up into multi-user mode; run-level 2.