Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Building an Extended Distance Cluster Using MC/ServiceGuard
Two Data Centers and Third Location Architectures
Chapter 2 63
The following is an example of a three data center configuration using
DWDM, with a quorum server node on the third site.
Figure 2-5 Three Data Centers with DWDM and Quorum Server