1-to-1 configuration

When setting up a one-to-one configuration (see Figure 2 (page 9)), consider the following:

•Cluster nodes are split between two or more geographically dispersed data center sites and use redundant, diversely routed network connections for intra-cluster communications. Those links must be as reliable as possible to prevent false failover operations or split-brain situations.

•Each cluster node connected to a HP 3PAR storage system should have redundant I/O paths to the HP 3PAR storage system. Connections to both the source (primary) and the destination (secondary) copy of the application disk set are not allowed from the same host. Configure your servers only in the zone that allows access to the local HP 3PAR storage system.

•HP recommends a minimum of two cluster nodes per site. This allows for preferred local failover in case of server system failure. Local failover operations are faster than remote failover between HP 3PAR storage systems because you do not need to change the mirroring direction of the Remote Copy volume group members.

•You can deploy HP 3PAR Cluster Extension in environments where several clusters use the same HP 3PAR storage system pair.

•You can use HP 3PAR Remote Copy in synchronous replication mode between two HP 3PAR storage systems connected using FC switches and extender hardware.

•HP 3PAR Cluster Extension supports synchronous replication mode in all the configurations supported by HP 3PAR Remote Copy Software.

•The HP 3PAR Remote Copy links must have redundant, separately routed links. The cluster network must have redundant, separately routed links. However, cluster networks and HP 3PAR Remote Copy can share the same links if the link technology is protocol independent (for example, WDM) or if the FC protocol is transformed into IP.

Figure 2 1-to-1 configuration

Storage system configurations

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