Dell PowerStore Configuring Multiprotocol File Sharing

UNIX security model

When the UNIX policy is selected, any attempt to change file level security from the SMB protocol, such as changes to Access Control Lists (ACLs), is ignored. UNIX access rights are named NFSv3 UNIX mode bits or NFSv4 ACL of a file system object. A bit string represents mode bits. Each bit represents an access mode or privilege that is granted to the user owning the file, the group associated with the file system object, and all other users. UNIX mode bits are represented as three sets of concatenated rwx (read, write, and execute) triplets for each category of users (user, group, or other). An ACL is a list of users and groups of users by which access to, and denial of, services is controlled.

The UNIX security model uses the NFSv3 UNIX mode bits or NFSv4 ACL for both protocols. When there is a request for SMB access, the UNIX credential that is built from the UDS/local files is used to check the NFSv3 mode bits or NVSv4 ACL for permissions. When NFSv3 UNIX mode bits or NFSv4 ACLs are changed, SMB ACL permissions are updated.

SMB ACL permission changes are allowed to avoid disruption, but are not maintained.