Information about this setup was shown by Thomas Merz in his
presentation at the SambaXP 2005, Reference
01-Thomas_Merz_-_Samba_als_AD_HA_Dienst.pdf (Title in german, Text in
english) 

Assumption:

You have 3 Samba Servers and one clusterfilesystem that they all can
access.

So what you do is that you create a directory on this CFS and set it
up like

/CFS/samba/intern/
/CFS/samba/shares/share1
/CFS/samba/shares/share2
/CFS/samba/shares/share3

within /CFS/samba/intern/ we create the following:

lrwxrwxrwx  1 rschmid users    9 2005-09-14 12:46 global -> @hostname
drwxrwxrwx  2 rschmid users 4096 2005-09-14 12:45 linux2
drwxrwxrwx  2 rschmid users 4096 2005-09-14 12:45 linux3
drwxrwxrwx  2 rschmid users 4096 2005-09-14 12:45 linux4
drwxrwxrwx  2 rschmid users 4096 2005-09-14 12:45 include


with this Server Linux2 would access "global" logically but the physical
location would be "linux2"

These are called "Context Dependant Path Name"
 
Then in "intern" we have "include", where we put our configuration files for
different services that should be available for the different servers.

They could look like

share2.conf

[share2]
	path=/CFS/samba/shares/share1
	comment = CAD
	read only = no

share3.conf

[share3]
	path=/CFS/samba/shares/share2
	comment = party pictures
	read only = yes

Now in the directory /CFS/samba/intern/linux2 we have the smb.conf for
linux2. This could look like

[global]
	....
	
	....
	
include = /CFS/samba/intern/include/share3.conf


In the directory /CFS/samba/intern/linux3 we have the smb.conf for
linux3. This could look like

[global]
	....
	
	....
	
include = /CFS/samba/intern/include/share2.conf
include = /CFS/samba/intern/include/share3.conf

So we have share3 served on both Servers parallel, this can be done,
but only if no parallel write access happens. Data corruption will
happen otherwise as Samba, resp the two Samba Servers cannot provide
reliable locking.