Microsoft Accounts (was Re: Problem with "None" Group on Non-Domain Members)

Chris J. Breisch chris.ml@breisch.org
Tue May 6 18:22:00 GMT 2014


Corinna Vinschen wrote:
> On May  6 13:01, Chris J. Breisch wrote:
>> Corinna Vinschen wrote:
>>> Other than that, I'm open to discuss the necessity(?) to override
>>> the primary group by default.  But, in fact, I'm not sure this really
>>> makes sense.  Linux systems default to creating a user-specific group
>>> account and using that as the user's primary group for years.  The
>>> Windows Account technique isn't quite as nice, but admittedly, it
>>> does its job just as well.
>> Yes, I've experienced that on Linux, but I don't recall having these
>> file permission issues there. Perhaps I just never noticed though.
>
> No, it *is* different,  On Linux you get a user account called "Chris"
> and a group account called "Chris", and they are different because users
> and groups are totally different beasts on POSIX systems.  You can have
> a user with uid 42 and a group with gid 42 and they are still different.
>
> On Windows, users and groups are identified not by uid/gid, but by
> their SID.  The SID is a unique value, but other than that, a SID can
> be a user or a group and in lots of cases Windows doesn't care.
> A group can be owner of a file and a user can be the group of the file,
> it just doesn't matter to Windows.
>
> The permission "problem" you're seeing is a result of that.  Your user
> *and* your primary group are both your user's SID.  Therefore the same
> account is user and primary group at the same time.  Therefore, if
> the file is created, it gets created with an ACL with user and group
> being the same account.  Therefore the POSIX translation of the user
> and group permissions on the file are always the same.
>
> Does this clear it up?

Yes, that makes complete sense. Thank you again.


-- 
Chris J. Breisch

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple



More information about the Cygwin mailing list