HP Tru64 UNIX and TruCluster Server Version 5.1B-5 Patch Summary and Release Notes (March 2009)

A Setting Up an Enhanced Distance Cluster
An Enhanced Distance Cluster allows a cluster to be extended between two sites up to
100 km apart to assist recovery in the event of a disaster. An Enhanced Distance Cluster
provides basic high availability services in the event of the loss of a single component.
It is important to note that an Enhanced Distance Cluster is not designed to handle nor
is it capable of handling simultaneous cascading failures and therefore can not provide
a fully disaster tolerant solution. The following topics are discussed:
• The section “Enhanced Distance Cluster Configuration Requirements” lists
configurations, features, and functions that must be present in order to have a
supported Enhanced Distance Cluster configuration.
• The section “Enhanced Distance Cluster Restrictions” (page 255) lists configurations,
features, and functions that cannot be present in order to have a supported
Enhanced Distance Cluster configuration.
• The section “Enhanced Distance Cluster Recommendations” (page 256) lists
configurations, features, functions that should be present, but are not required to
have a working Enhanced Distance Cluster.
A.1 Enhanced Distance Cluster Configuration Requirements
This section provides information on the hardware and configurations supported for
Enhanced Distance Clusters. Configurations that deviate from these configurations
will require a custom support statement from Hewlett Packard in order to be supported.
See the TruCluster Server QuickSpecs for information on hardware components
supported by the TruCluster Server product.
The following table lists supported hardware.
Table A-1 Hardware Configuration
2 to 4 nodesNumber of Nodes
Any node supported in a TruCluster configuration.CPU Type
Any Fibre Channel HBA supported by TruCluster. (Parallel SCSI is not supported
for any storage that can potentially fail over between locations.)
Fibre Channel
Adapter (HBA)
Gigabit Ethernet LAN with up to three switches. Cumulative distance must not
exceed 100 km.
Interconnect
TruCluster Fibre Channel connected storage (such as HP StorageWorks XP and
HP StorageWorks EVA).
Storage
The following list describes configuration requirements for the cluster:
• A two- to four-node cluster with up to three nodes at one site and the other nodes
at a different site.
• The cluster must be configured as a LAN cluster.
• A least one shared storage array must be present at each site.
A.1 Enhanced Distance Cluster Configuration Requirements 253