Skip to main content
NetApp Knowledge Base

root squashing causes Access Denied when mounting NFS export

  1. Last updated
  2. Save as PDF
Views:
14,600
Visibility:
Public
Votes:
5
Category:
ontap-9
Specialty:
nas
Last Updated:

Applies to

  • ONTAP 9
  • NFSv4
  • RHEL 7

Issue

  • Mounting an NFSv4 export as root on a RHEL client fails:

# mount -vv -o nfsvers=4.0,sec=sys nfsserver:/rootjunction/directory1/ /mnt/tmpmnt/
mount.nfs: timeout set for Thu Jan13 12:19:34 2022
mount.nfs: trying text-based options 'sec=sys,vers=4.1,addr=192.168.0.2,clientaddr=192.168.0.3'
mount.nfs: mount(2): Protocol not supported
mount.nfs: trying text-based options 'sec=sys,vers=4.0,addr=192.168.0.2,clientaddr=192.168.0.3'
mount.nfs: mount(2): Permission denied
mount.nfs: access denied by server while mounting nfsserver:/rootjunction/directory1

  • Mounting via NFSv3 may be successful
  • In vserver nfs show 
    • NFSv4 is enabled
    • mount-as-root is enabled
    • NFSv4-id-domain is set to the user's domain
    • default user is nobody
  • Linux access to unix security style volumes does not require name-mapping and configuration of user/group and permissions are desirable:
cluster1::*> vserver security file-directory show -vserver nfsserver -path /rootjunction

                Vserver: nfsserver 
              File Path: /rootjunction
      File Inode Number: 64
         Security Style: unix
        Effective Style: unix
         DOS Attributes:  10
DOS Attributes in Text: ----D---
Expanded Dos Attributes: -
           UNIX User Id: 0
          UNIX Group Id:  0
         UNIX Mode Bits: 2750
 UNIX Mode Bits in Text: rwxr-s---
                   ACLs: -
  • The export policy has root squashing configured

cluster1::> vserver export-policy rule show -vserver sv1 -policyname nfsexport -ruleindex 2 -instance

                                    Vserver: nfsserver
                                Policy Name: nfsexport
                                 Rule Index: 2
                            Access Protocol: nfs4
List of Client Match Hostnames, IP Addresses, Netgroups, or Domains: 192.168.0.0/24
                             RO Access Rule: any
                             RW Access Rule: any
User ID To Which Anonymous Users Are Mapped: 65534   
                   Superuser Security Types: none    
               Honor SetUID Bits in SETATTR: true
                  Allow Creation of Devices: true

  • It is successful when the directory being mounted has execute permissions

Sign in to view the entire content of this KB article.

New to NetApp?

Learn more about our award-winning Support

NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.