Dell Storage Manager 2020 R1 Administrator's Guide

File Security Styles

The Windows and UNIX/Linux operating systems use different mechanisms for resource access control. Therefore, you assign each NAS volume a file security style (NTFS, UNIX, or Mixed) that controls the type of access controls (permission and ownership) for the files and directories that clients create in the NAS volume.

A NAS volume supports the following security styles:

• UNIX – Controls file access using UNIX permissions. A client can change permissions only by using the chmod and chown commands on the NFS mount point.
• NTFS – Controls file access by Windows permissions. A client can change the permission and ownership using Windows (File Properties → Security tab).
• Mixed – Supports both NTFS and UNIX security styles. If you choose this option, the default security of a file or directory is the last one set. Permissions and access rights from one method to another are automatically translated. (For example, if a Windows administrator sets up file access permissions on a file through an SMB share, a Linux user can access the file system through NFS and change all the file permissions.) Therefore, this option is not recommended in production environments, except where you are not concerned about file access security and just need some NAS volume space to store files temporarily.

Both NTFS and UNIX security styles allow multiprotocol file access. The security style determines only the method of storing and managing the file access permissions information within the NAS volume.

If you need to access the same set of files from both Windows and UNIX or Linux, the best way to implement multiprotocol access is by setting up individual user mapping rules or by enabling automatic user mapping. Ownership and access permissions are automatically translated based on user mapping settings and file access credentials.

Modifying the file security style of a NAS volume affects only those files and directories created after the modification.