NFS Datastore Fails to Mount with "The mount request was denied by the NFS server" Error

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• When attempting to add an NFS datastore to an ESXi host, the operation fails with error message:

  "The following error is observed in the VMkernel logs,Unable to complete Sysinfo operation. Please see the VMkernel log file for more details"

• var/run/log/vmkernel.log on ESXi host will report error as "The mount request was denied by the NFS server"
  
  

  YYYY-MM-DDTHH:MM:SS.MsecZ cpu88:2101111 opID=8a38####) StorageApdHandler: 1051: Freeing APD handle 0x431df7c02c20 [f191d282-######]
  YYYY-MM-DDTHH:MM:SS.MsecZ cpu88:2101111 opID=8a38####) StorageApdHandler: 1135: APD Handle freed!
  YYYY-MM-DDTHH:MM:SS.MsecZ cpu88:2101111 opID=8a38####)NFS: 194: NFS mount 192.168.##.##:<share path> failed: The mount request was denied by the NFS server. Check that the export exists and that the client is permitted.

• Existing NFS datastore might show as inaccessible in the vCenter UI.
  
  

Environment

• VMware ESXi 7.x
• VMware ESXi 8.x

Cause

• The issue occurs due to access restrictions or misconfiguration on the NFS server. The NFS server may deny the mount request if:
• The NFS export does not exist.
• The ESXi host is not permitted access to the NFS share.

Resolution

1. Verify NFS Server Configuration:

• • Confirm that the NFS export path exists on the NFS server.
  • Ensure that the ESXi host has been granted appropriate permissions on the NFS server.

     2.Validate Network Connectivity:

• • Confirm that the ESXi can communicate with the NFS server.
  • Use the following commands to check connectivity:

    • vmkping vmkN <NFS_Server_IP>  

    • nc -vz <NFS_Server_IP> 2049 
      

     3. Check Firewall Rules and Export Settings:

• • Verify that there are no firewall rules blocking the connection between the ESXi host and the NFS server.
  • On the NFS server, ensure that the export configuration allows the ESXi host's IP address or subnet.\

     4. If the above checks do not resolve the issue, engage the storage team to review and correct the access settings on the NFS server.

Additional Information

• After resolving the access issue, retry the operation to mount the NFS datastore.
• To mount the NFS datastore from the ESXi CLI:

  • esxcli storage nfs add --host=<NFS_Server> --share=<NFS_Share_Path> --volume-name=<Datastore_Name>

Additional Information

Troubleshooting NFS datastore connectivity issues