/etc/sysconfig/nfs

NFS requires portmap, which dynamically assigns ports for RPC services. This causes problems for configuring firewall rules. To overcome this problem, use the /etc/sysconfig/nfs file to control which ports the required RPC services run on.

The /etc/sysconfig/nfs may not exist by default on all systems. If it does not exist, create it and add the following variables (alternatively, if the file exists, un-comment and change the default entries as required):

MOUNTD_PORT=x

control which TCP and UDP port mountd (rpc.mountd) uses. Replace x with an unused port number.

STATD_PORT=x

control which TCP and UDP port status (rpc.statd) uses. Replace x with an unused port number.

LOCKD_TCPPORT=x

control which TCP port nlockmgr (rpc.lockd) uses. Replace x with an unused port number.

LOCKD_UDPPORT=x

control which UDP port nlockmgr (rpc.lockd) uses. Replace x with an unused port number.

If NFS fails to start, check /var/log/messages. Normally, NFS will fail to start if you specify a port number that is already in use. After editing /etc/sysconfig/nfs restart the NFS service by running the service nfs restart command. Run the rpcinfo -p command to confirm the changes.

To configure a firewall to allow NFS:

  1. Allow TCP and UDP port 2049 for NFS.