Linux clients show incorrect UID/GID ownership on Windows NFS server.

Question

Windows Server 2022. All the Linux clients accessing our Windows NFS server show incorrect UID/GID ownership on files. I can check the shares and permissions, but shortly after mounting they still display the wrong UID/GID attributes. No files show the correct ownership in any share or directory.

I have checked the NFS service, cleared the cache, and remounted the shares. Same result. What's the correct Identity Mapping (AD-based or file-based) configuration to verify?

Answer 1

Hello Olivia Gonzalez,

Thank you for contacting Microsoft Q&A.

Based on your description, this behavior is commonly related to the NFS identity mapping configuration on the Windows NFS server. Since all Linux clients are displaying incorrect UID/GID ownership across all shares, we recommend verifying which identity mapping method is currently configured on the Windows Server. Windows NFS can use Active Directory-based mapping, LDAP/AD LDS, or local passwd/group mapping files.

Please check the current mapping configuration by running:

Get-NfsMappingStore

If Active Directory mapping is being used, confirm that the relevant user and group objects have valid uidNumber and gidNumber attributes configured. If file-based mapping is configured, please verify that the passwd and group mapping files contain the correct entries and are being referenced by the NFS service.

Additionally, it would be helpful to collect the following information:

• Output of Get-NfsMappingStore
• Output of Get-NfsMappedIdentity`` ``-AccountType`` ``User
• Output of Get-NfsMappedIdentity`` ``-AccountType`` ``Group
• Sample ls`` ``-ln output from one of the affected Linux clients

These details will help us determine whether the NFS server is using the expected identity mapping source or if it is falling back to an incorrect or unmapped UID/GID.

Hope you found something helpful here. Please let me know if you need further assistance.

If this answer could solve the issue, it's appreciated to accept the answer.

Thank you again for your patience and support!

Ivy Bui