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

Building a Continental Cluster
Designing a Disaster Tolerant Architecture for use with ContinentalClusters
Chapter 5194
many nodes as are permitted in an ordinary MC/ServiceGuard cluster,
and each may be running packages that are not configured to fail over
between clusters.
NOTE Remember that when cluster A takes over for cluster B, it must run
cluster B’s packages as well as any packages that it was already running
on its own, unless you choose to stop those packages.
Data Replication
Data replication between the MC/ServiceGuard clusters extends the
scope of high availability to the level of the continental cluster. You must
select a technology for data replication between the two clusters. There
are many possible choices, including:
• Logical replication of databases
• Logical replication of filesystems
• Physical replication of data volumes via software
• Physical replication of disk units via hardware
Table 5-3 is a brief discussion of how a data replication method affects a
continental cluster environment. A detailed description of data
replication can be found in Chapter 1, in the section titled “Disaster
Tolerant Architecture Guidelines.” Specific guidelines for configuring the
HP StorageWorks E Disk Array XP Series and the EMC Symmetrix Disk
Array for physical data replication in a continental cluster are provided
in Chapters 6 and 7. In order to use these data replication solutions in a
ContinentalClusters environment you will need to purchase
MetroCluster/CA and MetroCluster/SRDF products separately.
White papers describing specific implementations are also available from
http://docs.hp.com/hpux/ha.
If you choose a data replication technology that is not mentioned above,
and if you want to do your own integration, you have to use the
guidelines described in section, Using the Recovery Command to Switch
All Packages. In that case, note the following: