[Samba] CTDB with 3 nodes and local disks without a dedicated SAN

[Max]

  Hello,

First, sorry, I know that this is by far not 100% samba related but 
since this setup is exclusively for samba + CTDB and as such is no 
ordinary setup, I thought it might be good to ask here.

I'm having a hard time figuring out how to accomplish the following:


I'd like to set up 3 samba nodes clustered with CTDB, with each 
node/machine having its own sets of local disks.
It would be great if 2 machines and/or sets of local disks could fail 
the same time without taking down samba.

Is this only possible using DRBD as suggested in the current Samba 3 book?
As I understand DRBD only allows 2 nodes and an optional 3rd for 
disaster recovery.

Does anyone have any idea or recommendations on how to do this without 
DRBD's limitation of 2 storage nodes?

Thank you very much for any help!

Regards,

Max