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

Building a Metropolitan Cluster Using MetroCluster/CA
Designing a Disaster Tolerant Architecture for use with MetroCluster/CA
Chapter 3 73
Two Data Centers and Third Location with
Arbitrator(s)
This is the recommended and supported disaster tolerant architecture
for use with MetroCluster/CA. This architecture consists of two main
data centers with an equal number of nodes and a third location with one
or more arbitrator nodes or a quorum server node; see Figure 3-1.
Figure 3-1 Two Data Centers and Third Location with Arbitrators
The local XP Series disk array is called the Main Control Unit (MCU)
for all nodes and packages in a given data center. The remote XP Series
disk array, where the data is replicated, is called the Remote Control
Unit (RCU). Note that main and remote are relative terms. An XP
CA link
node 1
pkg A
Data Center A
Highly Available
node 2
pkg B
PVlinks
network
CA link
network
PVlinks
Network
arbitrator 1
Third Location
arbitrator 2
networknetwork
Power
Power Circuit 5 Power Circuit 6
Circuit
1
A
Power
Circuit
2
node 1a
pkg C
Data Center B
node 2a
pkg D
PVlinks
network
network
PVlinks
Power
Circuit
3
Power
Circuit
4
B
D
1
C
1
C
D
B
1
A
1
Local XP
Disk Array
Remote XP
Disk Array
PVOL SVOL
replicated data for package A
PVOL SVOL
replicated data for package B
SVOL PVOL
replicated data for package C
SVOL PVOL
replicated data for package D
or Quorum Server