NFS export keeps hanging without log messages

Q I'm trying to mount an NFS export from my server to my workstation, and it keeps hanging. There is nothing in any logs to indicate what's going wrong - are there any common causes?

A NFS relies on a number of RPCs, or remote procedure calls. The key to all of this is the portmap service. This processes RPC requests and sets up connections to the correct RPC. Check that it's running by looking at the process list:

[root@test gnump3d-2.9.8]# ps -ef | grep portmap
rpc    2584 1 0 Jul23 ?         00:00:00 portmap
root 30843 30474 0 07:45 pts/4 00:00:00 grep
portmap

Assuming your NFS server service is started, you should see the following RPCs running: mountd, nfsd, lockd, statd, lockd, rquotad and idmapd. Depending on your distribution these may be started by the startup script for NFS. If they aren't, it's possible to start them manually:

[root@test]# rpc.mountd
[root@test]# ps -ef | grep mountd
root 30906 1 0 07:54 ?            00:00:00 rpc.
mountd

You can repeat this for the other services, but you will need to add them to the appropriate startup script to ensure that they are restarted at boot time.

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