nfs connectivity issuses

Hello Shing Fan LEE,
You’re seeing NFS connectivity issues—if your NFS share has been down all day, the root cause is often one of a few common Azure Files NFS conditions: missing NFS client packages, network/firewall blocking port 2049, storage account network access (untrusted client), or secure-transfer/encryption settings mismatch.

Here are the most useful checks to try for Azure Files NFS:

1) Confirm the NFS utilities are installed (Linux)

Before mounting, install one of:

• nfs-utils (RHEL/CentOS/Oracle Linux)
• nfs-client (SLES)
• nfs-common (Ubuntu/Debian)

Example install commands:

• RHEL/CentOS:
• sudo yum install nfs-utils (or sudo dnf install nfs-utils on newer versions)
• Ubuntu:
• sudo apt update && sudo apt install nfs-common

2) Verify port 2049 is reachable

Azure Files NFS uses TCP 2049. Make sure it’s open from the client to the storage account’s NFS endpoint.

Run from the client:

sudo nc -zv <storageaccountname>.file.core.windows.net 2049

If this fails, your firewall/NSG/network path is likely blocking port 2049.

3) If it is “untrusted,” ensure correct endpoint configuration

For NFS, auth is based on network security rule configuration (not user-based auth). If you are from an untrusted network/IP, mounting can fail.

Use one of:

• Service endpoint
• Private endpoint

(For on-prem access with private connectivity requirements, you may also need VPN/ExpressRoute.)

4) Check Secure transfer / encryption-in-transit settings for NFS mounts

If the storage account enforces secure transfer/encryption in transit for NFS, mounting can fail—especially if you’re not using the recommended mount helper.

For NFS encryption-in-transit:

• Use the AZNFS Mount Helper for NFSv4.1 TLS tunnels, or
• Disable the relevant secure settings on the storage account (per the guidance) if you don’t need encrypted-in-transit NFS.

5) Double-check you’re mounting with the right options/protocol version

Incorrect mount options can cause mount failures (for example, errors like “incorrect mount option”). Also ensure both sides use compatible NFS versions (Azure Files NFS is commonly mounted as NFSv4.1).

Can you please update us if the action plan provided was helpful?

Should there be any follow-up questions or concerns, please let us know and we shall try to address them.

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