NFS suddenly stopped working

Question

NFS suddenly stopped working

Kai 0

Hello, our blob storage with NFS shares are not showing any files suddenly. Is something down?

Vallepu Venkateswarlu 7,400 Reputation points Microsoft External Staff Moderator

2026-04-01T20:49:35.9966667+00:00
Hi @ Kai ,

Welcome to Microsoft Q&A Platform.

If suddenly your NFS mount is up but suddenly showing an empty directory. Azure Blob NFS isn’t generally “down,”

Verify the blobs still exist :
Inn the Azure portal or with the CLI run:

az storage blob list --account-name <account> --container-name <container> --auth-mode login

You can also check the files in the Azure portal. If you do not see your files there, they may have been deleted or moved. You can review the Activity Logs of the storage account to verify any related operations.

If the files exist in Blob Storage but are not appearing in NFF, please follow the troubleshooting steps below:

Unmount/remount to clear client cache : Mount the container

sudo umount /mnt/nfs sudo mount -t nfs -o vers=3,nolock .blob.core.windows.net:/ /mnt/nfs # <storage-account-name>.blob.core.windows.net:/<storage-account-name>/<container-name> /nfsdata aznfs defaults,sec=sys,vers=3,nolock,proto=tcp,nofail,_netdev 0 0 sudo mount /nfs

“nolock” is required because Azure Blob NFS doesn’t support NLM locking.

Check network & firewall rules

• NFS v3 on Blob Storage only uses TCP 2049. Test connectivity:

nc -zv .blob.core.windows.net 2049

Ensure no NSG or firewall is blocking 2049 end-to-end (on-prem → service endpoint or private endpoint).

Mount the root of the container only (no subdirs).

Beware of hidden characters if you copy/paste the command.

Review permissions & ACLs

You need Storage Blob Data Contributor (or higher) on the account or container.

If you enabled any named-user/group ACL entries, remove them – Azure Blob NFS can’t honor those and will block non-root users.

Client prerequisites • Linux kernel ≥ 4.3 and nfs-utils (or equivalent) must be installed.

Windows NFS clients are not supported – use WSL2 as a workaround if on Windows.

If after these steps your mount is still empty or you see errors (e.g., “access denied,” timeouts, “no such file or directory”), let us know the exact error message and any recent changes you made (mount command, network, storage account config).

Resolve common errors by following the link here

If the above steps did not help resolve your issue, please feel free to share the details in a private message so we can proceed with further troubleshooting over a Teams call. I am happy to connect with you on Teams to investigate and resolve the issue

Please "upvote" if the information helped you. This will help us and others in the community as well.
Kai 0 Reputation points

2026-04-01T22:10:39.7866667+00:00

When i try to access the storage browser in the web, it is showing no items found for the NFS shares.
Kai 0 Reputation points

2026-04-01T22:33:42.8766667+00:00

Here is the error i get when i try to remount

reason given by server: No such file or directory
Vallepu Venkateswarlu 7,400 Reputation points Microsoft External Staff Moderator

2026-04-02T00:44:52.7166667+00:00
Hi @ Kai ,

Thank you for your response.

If Azure Portal (Storage Browser) is also showing “no items found”, then this is not an NFS mount issue — it’s either:

NFS in Blob works at container level, not like folders.

Make sure you are opening the correct container

Not another empty container

Check using CLI (bypass portal):

az storage blob list --account-name <account> --container-name <container> --auth-mode login

If all the options are showing empty, please try uploading some test files and check if they appear in NFS.

If all files are suddenly not visible, please check the Activity Log in the Azure portal by navigating to Azure Portal → Storage Account → Activity Log

Apply the following filters:

Delete Blob

Delete Container

Write operations

If any data was deleted, the corresponding operations will be visible in the logs.

Note: Also verify that you have the required permissions (e.g., Storage Blob Data Contributor) and check the storage account firewall settings to ensure proper access.

If still same issue please share the requested details in Private message for further troubleshoot.

Refer:

Mount Blob Storage by using the Network File System (NFS) 3.0 protocol
Known issues with Network File System (NFS) 3.0 protocol support for Azure Blob Storage

Please "upvote" if the information helped you. This will help us and others in the community as well.
Ganesh Patapati 11,915 Reputation points Microsoft External Staff Moderator

2026-04-08T16:04:19.9633333+00:00
Hello Kai

NFS version mismatch between the server and client can indeed lead to the error “mount.nfs: No such file or directory”.

NFS has different versions like NFSv3, NFSv4. Sometimes, the server and the client may be using different versions of NFS which can lead to compatibility issues.

In case the NFS version used by your client is higher than the server, you can force your client to use the same version as the server during the mount process. This can be done by specifying ‘vers=x’ (replace x with the version number) in the mount options.

For example, if your server is running NFSv3, the mount command would look something like this:

mount -t nfs -o vers=3 server:/path/to/directory /local/mount/point

This should resolve the error if it was caused due to a NFS version mismatch.

Also,

The successful NFS mount confirms the storage service is reachable; however, the sudden loss of file visibility is typically due to recent ACL or identity permission changes—while the files may still exist, they can become inaccessible when directory-level ACL restrictions are applied, which results in this expected behavior.

Please verify file visibility through the Azure Portal (Container → Browse) or by using the Azure CLI with an authenticated identity; if the files are visible using these methods, it confirms the issue is due to an ACL or permission mismatch rather than data loss or a storage outage.

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.
Ganesh Patapati 11,915 Reputation points Microsoft External Staff Moderator

2026-04-13T14:41:35.7033333+00:00

Hello Kai

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.