The setup that is shown in Figure 2-21 shows the configuration after a merge of grids. Before  the merge, the grids were only spread across 10 km (6.2 miles). The client’s requirements  changed. The client needed a third copy in a data center at a longer distance.  By merging environments, the client can address the requirements for DR and still use the  existing environment.  8464ch02_Architecture.fm Draft Document for Review February 7, 2020 3:15 pm Example 4: Four-cluster grid in three locations  Figure 2-21 Four-cluster grid in three locations Host A Site/Campus A FICON TS7740 or TS7700T Cluster 2 Host B FICON Site/Campus B FICON Ho TS774 TS770 Cluste TS7700D Cluster 1 Site/Campus C TS7740 or TS7700T Cluster 2 Host C Ho Ho WAN TS7700D  Cluster 0 Chapter 2. Architecture, components, and functional characteristics  107