Troubleshoot NFS Errors

Setting up and configuring an NFS server should be performed by your infrastructure team. If you experience problems with any of the following instructions, contact your infrastructure team for assistance.

You must have a connection from each node to NFS.

“Server Not Responding”

Use a tool such as ping, traceroute, or tracepath to verify that the client and server machines can communicate with each other. If communication fails between the client and server machines, examine the network interface card (NIC) settings using either ifconfig or ethtool to verify the IP settings.

“mount clntudp_create: RPC: Port mapper failure – RPC: Unable to receive”

The Linux NFS implementation requires that both the NFS service and the portmapper (RPC) service are running on both the client and the server. Verify that these services are running like this:

23:59:54 root@ip-10-1-1-215:/# rpcinfo -p
   program vers proto   port  service
    100000    4   tcp    111  portmapper
    100000    3   tcp    111  portmapper
    100000    2   tcp    111  portmapper
    100000    4   udp    111  portmapper
    100000    3   udp    111  portmapper
    100000    2   udp    111  portmapper

“Access Denied” or "Permission Denied"

Check the export permissions for the NFS file system. You can do this from the client or from the server.

From the client:

showmount -e server_name

From the server:

exportfs -a

"rpc mount export: RPC: Timed out"

The error message Unable to access file system at [NFS SERVER]: rpc mount export: RPC: Timed out is caused by a DNS name resolution issue. NFS (RPC) needs reverse name resolution. If the NFS server or client cannot resolve their name, this error occurs. Check the DNS configuration and the /etc/hosts configuration.

Mounting the NFS Server Fails

If the mount fails, you are probably missing some NFS-required libraries. If this happens, install them by running:
yum install nfs-utils nfs-utils-lib

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