NTFS Inheritance Rule Change

Testing under Windows Server 2008 SP2 shows that this behavioral change only affects moves done using the GUI. If you move a file or folder from a Command Prompt using the move command, the permissions do not get updated to reflect the permissions in the new location. Microsoft evidently decided to modify Explorer so as to compensate for the underlying issue, but did not modify the behavior of the underlying APIs. This is understandable given the complexity of modifying the underlying file system behavior without sacrificing the atomic nature of moving files and folders.

If you are running Windows Server 2008 file servers but still have users on XP and they do moves using the GUI, the permissions will be improperly inherited because Microsoft left it the responsibility of the GUI to fixup the permissions.

See the Perl module Win32::Security for a tool that can assist in identifying improperly inherited permissions that result from moves between locations with dissimilar inheritable permissions.

tovod-everett November 24, 2009 (Article Rating: )

Thanks for this important info

TerDale3 November 25, 2009 (Article Rating: )

Very interesting read indeed!
Question (also in respect of the comment by tovod-everett) is then if the desired behaviour (a move does cause inheritance updates of NTFS permissions of the moved object(s) to those of it's new parent) in a scenario with a Windows Server 2008 SP2 (e.g. Enterprise Edition) with File Services Role hosting file shares and Windows 7 clients; i.e. when a user on a Windows 7 client, move a folder/files within a file share hosted by the mentioned server on it's "same" disk?
As I haven't yet got a Windows 7 client I can test this with in my productive environment, would llike to learn from your experience/knowledge.

slemmesmi December 14, 2009 (Article Rating: )

Slemmesmi, there are two cases:
1) Legacy clients (2000, XP and 2003) may access the files remotely thru the shares and move the files from GUI. In this case, the former inheritance rule is applied; that is, if the files are moved to a folder on the same disk partition, they do not acquire the new folder's permissions, they keep their original NTFS permissions.
2) New clients (Vista, 2008 and Windows 7) may access the files remotely thru the shares and move the files from GUI. In this case, the new inheritance rule is applied and the files acquire the new folder's permissions.

Yes, it is very confusing and may result in some unexpected file operations. It is a shame Microsoft hasn't explained these point widely.

muraty December 16, 2009 (Article Rating: )