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

Disaster Tolerance and Recovery in an MC/ServiceGuard Cluster
Types of Disaster Tolerant Clusters
Chapter 124
In addition, there is no hard requirement on how far the third location
has to be from the two main data centers. The third location can be as
close as the room next door with its own power source or can be as far as
in a site across town. The distance between all three locations dictates
the level of disaster tolerance a metropolitan cluster can provide.
Metropolitan cluster architecture is implemented through two HP
products:
• MetroCluster with Continuous Access XP (described in Chapter 3)
• MetroCluster with EMC SRDF (described in Chapter 4)