[Samba] how to limit the size of a samba 3 share?

[samba.20.bogaard at spamgourmet.com]

Hello Samba list,

I have a customer that really needs to have its Samba shares hard-limited to
a 
certain size.
We migrated them from Novell Netware 5 to Whitebox Enterprise Linux 3 with 
Samba 3 with LDAP backend.
We've set UNIX acls on the share folders and subfolders, since they have 
specific wishes that cannot be covered with standard permissions (multiple 
groups should be able to read and/or write)
The need for this and the share size limit comes from their Novell 
experiences, with which this is all possible.
I've been able to cover all their 'access' wishes, but the share size 
limitation remains.
The shares are all now simply on one partition.

As far as I've been able to research, there is no possibility to really set 
a harddisk limit on a share (or a directory).
Am I correct? Have to admit that I was surprised by this, I expected that 
this would be possible, to me it occurs as a logical wish / need for many 
server admins.
There seem to have been attempts for Samba 2.x but they are not 
available/working for 3.x.?!

As far as I can judge, user and group quotas will not help me here, they 
have a lot of different groups and users are in multiple groups.
All users have "Domain Users" as their primary group

How can I achieve the (more or less) the same result?
I thought of repartitioning the drive and placing every share on its own 
partition.
Does this make sense? I need to be able to adjust the sizes easily.
Does LVM help me here?

Can I somehow maybe limit the size of a directory instead?
Are there any other mechanisms that I've overseen or does somebody know any 
workarounds.

I know, a lot of questions, but they remains unanswered after reading a lot 
of docs (including Samba 3 by Example, great book John)
So any feedback will really be appreciated

TIA

Mark van den Bogaard