UNIX security mode
When the server is configured in UNIX security mode, it supports UNIX security for SMB and NFS clients. However, all security settings are saved with UNIX file attributes. As a result, NFS clients are always accessing files in native mode, while SMB clients are always accessing file non-native mode.
NoteWith UNIX security mode, NFS users do not need to rely on the presence of a Windows domain controller (DC) in order to access files. As a result, they are fully isolated from potential DC failures.