Disaster Recovery Implementations; Stretch Clusters Vs. Cluster Of Clusters - Novell BUSINESS CONTINUITY CLUSTERING 1.1 SP1 - 9-21-2010 ADMINISTRATION GUIDE FOR OPEN ENTERPRISE SERVER 1 SP2 LINUX Administration Manual

1.2 Disaster Recovery Implementations

There are two main Novell Cluster Services implementations that you can use to achieve your
desired level of disaster recovery. These include a stretch cluster and a cluster of clusters. The
Novell Business Continuity Clustering product automates some of the configuration and processes
used in a cluster of clusters.

Section 1.2.1, "Stretch Clusters vs. Cluster of Clusters," on page 10

Section 1.2.2, "Novell Business Continuity Clusters," on page 13

Section 1.2.3, "Usage Scenarios," on page 14

1.2.1 Stretch Clusters vs. Cluster of Clusters


"Stretch Clusters" on page 10

"Cluster of Clusters" on page 11

"Implementation Comparison" on page 12
Stretch Clusters
A stretch cluster consists of one cluster in which the nodes in the cluster are located in
geographically separate areas. All nodes in the cluster must be in the same eDirectory™ tree. In this
architecture, the data is mirrored between two data centers that are geographically separated. All the
machines in both data centers are part of one cluster, so that if a disaster occurs in one data center,
the other automatically takes over.
Figure 1-1
Server 1
Fibre Channel
Switch
10 Novell Business Continuity Clustering 1.1 Administration Guide for Linux
Stretch Cluster
Building A
Ethernet Switch
Server 2 Server 3 Server 4
Fibre Channel
Disk Array
Site 1
8-node cluster stretched
between two sites
WAN
Cluster
Heartbeat
Server 5
SAN
Disk blocks
Building B
Ethernet Switch
Server 6 Server 7 Server 8
Fibre Channel
Switch
Fibre Channel
Disk Array
Site 2