Linux NFS Troubleshooting

Internal

• Linux NFS
• Linux NFS Installation

List Filesystems Exported by a NFS Server

exportfs: list filesystems exported by a NFS server

Verbose mount

Try to mount with -v (verbose). For more details see mount.

Other Useful Commands

showmount

showmount -e

on the server to see what is exported.

rpcinfo

rpcinfo

exportfs

exportfs

Failures

mount hangs

I've seen cases when trying to mount a filesystem from other machine hangs if nfs is not started on that machine (service nfs start).

mount.nfs: access denied by server while mounting

I've also seen cases when I get the following error message when not using -t nfs, so use -t nfs:

mount.nfs: access denied by server while mounting f01:/opt/shared

mount(2): No such file or directory

mount -v yields:

mount.nfs: trying text-based options 'bg,vers=4,addr=172.31.20.184,clientaddr=172.31.21.24'
mount.nfs: mount(2): No such file or directory
...

I get this because I use the wrong exported path in /etc/fstab.

mount(2): No route to host

mount -v yields:

mount -v -t nfs 192.168.1.2:/volume3/dropbox /mnt/tmp
mount.nfs: timeout set for Sun Aug 21 00:44:48 2016
mount.nfs: trying text-based options 'vers=4,addr=192.168.1.2,clientaddr=192.168.1.9'
mount.nfs: mount(2): No route to host

This error means that the NFS client host is not getting a TCP/IP ACK back from the NFS server.

The problem went away after configuring iptables to allow all outbound traffic (see iptables Service Configuration).

mount(2): Permission denied

mount -v yields:

mount -v -t nfs 192.168.1.4:/volume3/dropbox /mnt/tmp
...
mount.nfs: mount(2): Permission denied
mount.nfs: access denied by server while mounting 192.168.1.4:/volume3/dropbox

The error is paired with the following on the server-side:

Aug 21 01:35:58 RackStation mountd[11206]: refused mount request from 192.168.1.9 for /volume3/dropbox (/volume3/dropbox): unmatched host