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NetApp Knowledge Base

Access denied when mounting NFS export

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2,387
Visibility:
Public
Votes:
1
Category:
ontap-9
Specialty:
nfs
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
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