This controls how the DOS read only attribute should be mapped from a UNIX filesystem. This parameter can take three different values, which tell smbd 8 how to display the read only attribute on files, where either is set to No, or no extended attribute is present. If is set to yes then this parameter is ignored. This is a new parameter introduced in Samba version 3.0.21. The three settings are : Yes - The read only DOS attribute is mapped to the inverse of the user or owner write bit in the unix permission mode set. If the owner write bit is not set, the read only attribute is reported as being set on the file. If the read only DOS attribute is set, Samba sets the owner, group and others write bits to zero. Write bits set in an ACL are ignored by Samba. If the read only DOS attribute is unset, Samba simply sets the write bit of the owner to one. Permissions - The read only DOS attribute is mapped to the effective permissions of the connecting user, as evaluated by smbd 8 by reading the unix permissions and POSIX ACL (if present). If the connecting user does not have permission to modify the file, the read only attribute is reported as being set on the file. No - The read only DOS attribute is unaffected by permissions, and can only be set by the method. This may be useful for exporting mounted CDs. Note that this parameter will be ignored if the parameter is set, as the DOS 'read-only' attribute will then be stored inside a UNIX extended attribute. The default has changed to no in Samba release 4.9.0 and above to allow better Windows fileserver compatibility in a default install. In addition the default setting of has been changed to Yes in Samba release 4.9.0 and above. no