NFS permissions issues

Symptoms

 "Permission Denied" error message when trying to read/write an NFS share

Purpose

This article will discuss several reasons for "Permission Denied" error and how to resolve them

Resolution

1- Make sure that the NFS share is mounted

If it is not mounted and client does not have write permissions to the mount point, a permission denied error may occur


2- Check the share/directory permissions from the client side

In the below example, the user "asalah", is not the owner of the share, and the share only has write permissions for root.


3- Make sure the user has the correct user-to-UID mapping.

NFS does not have a method to retain or store users data, it only uses the default /etc/passwd [unless joined to AD], so the user-to-uid should be the same on both the server and all of the clients.

For example we have a user called "asalah" with UID= on the server he has rwx permissions on the Data directory

On the client side, the user "asalah" has a different UID, when you list the content of the Data directory [if permitted], you will find strange numbers instead of the username


If that UID is resrved for "userA" on the client, you will find that this share is owned by "userA" on the client and "asalah" on the server, so it is all about UIDs and which users own those UIDs on SoftNAS and all the clients


Update History

12-28-2018 Template Created