Linux NFS Troubleshooting: Difference between revisions

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       need a /sbin/mount.<type> helper program)
       need a /sbin/mount.<type> helper program)


Usually caused by the fact that the client libraries have not been installed. Fix it with
Usually caused by the fact that the client libraries have not been installed. Fix it by [[Linux_NFS_Installation#Install_Client_Packages|installing client packages]].

Revision as of 03:07, 15 May 2018

Internal

List Filesystems Exported by a NFS Server

exportfs: list filesystems exported by a NFS server

List Filesystems Mounted by a NFS Client

mount: list filesystems mounted by a NFS client

Useful Commands

verbose mount mount -v
showmount
rpcinfo
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

The root cause was the fact 192.168.1.9 was not specifically allowed access in the server's /etc/exports.

mount: wrong fs type, bad option, bad superblock on ...

mount: wrong fs type, bad option, bad superblock on 192.168.1.4:/volume1/nfstest,
      missing codepage or helper program, or other error
      (for several filesystems (e.g. nfs, cifs) you might
      need a /sbin/mount.<type> helper program)

Usually caused by the fact that the client libraries have not been installed. Fix it by installing client packages.