Question on short/mangled file name.

[Jeremy Allison]

On Wed, Oct 01, 2014 at 04:33:12PM -0700, Hemanth Thummala wrote:
> Hi folks,
> 
> I could see the short file name generated by Samba(3.6.12) is different
> from windows.
> 
> For example, a folder named "This is large folder". Samba generates the
> short name something like TYP843~9 where as windows gives as THISIS~1.
> 
> I found that smb.conf parameter(mangle prefix) which controls the prefix
> characters. I have changed that to 6. Even after that samba generate the
> name as THIS_I~K. I did not see any param to control the postfix. Mangling
> method is set to default one (hash2).
> 
> Would like to know the reason for choosing different name generation
> compared to windows. Not sure if some of the old windows versions are
> generating this way. I am comparing with windows 2k8 server version. Also
> would like to know if this is been addressed in samba 4.X. We are currently
> running 3.6.12 stack.

All short name generation algorithms can lead to collisions.
The hash2 Samba one generates less collisions that the Windows
one.

> This incompatibility of short names is actually affecting windows client's
> behavior.

How :-). This you're gonna have to *prove* :-).

Remember, a client only caches short names from
the server it connected to. The only way this
could cause an issue is if you replaced a Windows
server with a Samba one giving the same name and
IP address so the client thought it was talking
to the same box.

That isn't a supported configuration here. Call
the server something else.

Jeremy.