Hi,  You need a third element in this equation - you can think of a FaultSet as of a 'big SDS' - in order to form a cluster, you need 3 SDS, or, in this case, 3 FS. You can mix them, so for example you can have 2 FS and a single SDS, 1FS and 2 SDS, 3 FS etc., but in general FS acts as a single cluster member, so you need at least three.  In this case, I would suggest you to move one machine to a third rack or add another 1-2 nodes and create third FaultSet.  Please check out ScaleIO User Guide, under 'Fault Sets' sections there's much more details about the FS.  Hope that helps!  Cheers, Pawel
Hi there,   i am a little bit confused. maybe someone have some tipps.   I have 4 nodes. Two of them in one Rack/Room and the other two of them also in one Rack/Room.   ---------------------------------------------- -- node1     |       node3  -- -- node2     |       node4 -- -----------------------------------------------   how i have to configure the FaultSets/SDS/Pools/Protected Domains to get a catched up a location failover (two nodes on one side) so that i have no risk of a downtime.   any ideas ?   Thx.
EMC ScaleIO question / understanding about faulsets