[DRBD-user] 2 x 2-node configuration?

[Jaap Winius]

Hi folks,

My RHEL7 project is considering using DRBD to create sets of 2 x  
2-nodes that replicate synchronously across two data centers. The  
first half of each set would consist of a primary and a secondary with  
the latter taking over in case of failure (Heartbeat-based Pacemaker  
cluster). However, the same block device(s) should also replicate to  
the second half of the set in the second data center. Crucially, it  
should be possible to turn these roles around without too much effort  
when the choice is made to make the second data center active and the  
first one passive.

Is this possible with DRBD and if so, what kind of replication  
configuration should be used?

Thanks,

Jaap