Table 9 Data Replication and Continentalclusters (continued)

Replication Type

How it Works

Continentalclusters Implication

replication inappropriate for Continentalclusters.

Physical Replication of Disk

Replication of the LUNs across disk

Units via Hardware

arrays through dedicated hardware links

 

such as EMC SRDF, or Continuous

 

Access P9000, or XP, or Continuous

 

Access EVA, or 3PAR Remote Copy.

Limited CPU requirements, but the requirement of synchronous data replication slows replication, and may impair application performance. Increased network speed and bandwidth can remedy this.

Logical data replication may require the use of packages to handle software processes that copy data from one cluster to another or that apply transactions from logs that are copied from one cluster to another. Some methods of logical data replication may use a logical replication data sender package, and others may use a logical replication data receiver package while some may use both. Logical replication data sender and receiver packages are configured as part of the data recovery group, as shown in section, “Preparing the Clusters” (page 54).

Physical Data Replication

For physical data replication, Continentalclusters uses pre-integrated solutions, which uses Continuous Access P9000 or XP, Continuous Access EVA , EMC SRDF, and 3PAR Remote Copy. To use these data replication solutions in Continentalclusters environment it is necessary to purchase either the Metrocluster with Continuous Access for P9000 and XP, or Metrocluster with Continuous Access EVA, Metrocluster with EMC SRDF, or Metrocluster with 3PAR Remote Copy products separately.

Physical data replication generally does not require the use of separate sender or receiver packages.

Using Modular Packages

When any of these pre-integrated solutions are used, the corresponding Continentalclusters specific module must be included to the primary and recovery packages. The packages that use physical data replication with the HP StorageWorks P9000 Disk Array family or HP StorageWorks XP Disk Array series with Continuous Access P9000 and XP should use the dts/ccxpca module to configure the primary and recovery packages. For packages that use physical data replication with HP StorageWorks Disk Array EVA with Continuous Access EVA should use the "dts/cccaeva" module to configure the primary and recovery packages. Packages that use physical data replication with EMC Symmetrix and the SRDF facility should use the "dts/ccsrdf" module for configuring the primary and recovery packages. The packages that use physical data replication with the HP 3PAR Storage Systems with 3PAR Remote Copy should use the dts/cc3parrc module to configure the primary and recovery packages.

For more information, see Configuring Primary and Recovery Packages as Modular Packages.

Using Legacy Packages

The packages that use physical data replication with the HP StorageWorks P9000 Disk Array family or HP StorageWorks XP Disk Array series with Continuous Access P9000 and XP should have created a specific environment file using template /opt/cmcluster/toolkit/SGCA/

xpca.env

Packages that use physical data replication with HP StorageWorks Disk Array EVA with Continuous Access EVA should be created using /opt/cmcluster/toolkit/SGCA/caeva.env, and packages that use physical data replication with EMC Symmetrix and the SRDF facility should be created using /opt/cmcluster/toolkit/SGSRDF/srdf.env.

These templates are available with the products Metrocluster with Continuous Access for P9000 and XP, or Metrocluster with Continuous Access EVA, or Metrocluster with EMC SRDF.

NOTE: Metrocluster with 3PAR Remote Copy is not supported with legacy packages, and therefore it does not provide a special environment file template with the product.

50 Designing Continentalclusters