Data Replication Connections

The remote copy connections are the physical paths used by the primary array to communicate with the secondary array. The primary P9000 or XP array and secondary P9000 or XP array are connected using fiber-channel interface (Note: ESCON is not supported with the XP12000). Ensure the connection is established in a bidirectional manner.

Metrocluster package vs. Journal Group

Metrocluster with Continuous Access for P9000 and XP supports only one journal group pair per package. Thus, in a metropolitan cluster, the number of packages can be configured to use journal group is limited by either the maximum number of journal groups that are supported by the P9000 or XP in the configuration, or by the maximum number of packages in the cluster, which ever is smaller.

Metrocluster with Continuous Access for P9000 and XP and Thin Provisioning Volumes

Metrocluster with Continuous Access for P9000 and XP includes support for Thin Provisioning Volumes (TP-VOLs) only on arrays XP20000, XP24000, P9500 and beyond, and P9000 disk array family. When TP-VOLs are configured, there is a possibility that the TP-VOL utilization could exceed the specified capacity or threshold of the pool. When this threshold is exceeded, the state of all pool volumes are marked as BLOCKED. As a result, no I/O can be written to the TP-VOLs, and subsequently, the Metrocluster package fails. However, the package failover fails in the remote site, as the pools at the remote site are also marked as BLOCKED, since the configuration is symmetric with the configuration at the primary site.

To overcome this problem, the pool utilization must be manually monitored to determine when the predefined threshold is achieved. By monitoring the utilization, additional storage space can be allocated to the pool as and when required.

For more information about configuring and monitoring Thin Provisioning volumes, see the HP StorageWorks P9000 Provisioning for Open Systems User Guideor HP StorageWorks XP24000/XP20000 Thin Provisioning Software User's Guide at:

http://bizsupport1.austin.hp.com/bizsupport/TechSupport/ProdSearch.jsp? prod=HP%20StorageWorks—> HP StorageWorks XP Array Manager Software —> Manuals.

Following are the guidelines that must be considered for configuring Thin Provisioning Volumes in a Continuous Access Pair:

•This feature is supported on arrays XP20000, XP24000, P9500 and beyond.

•The Primary Volumes (P-Vol) and Secondary Volumes (S-Vol) must be Thin Provisioning Volumes. A combination of regular volumes with Thin Provisioning volumes is not supported.

•Only Continuous Access Synchronous and Journal configurations are supported with Thin Provisioning Volumes.

•All synchronous fence levels with the values set as data and never are supported.

•Journal volumes cannot be TP-VOL.

•Pool volumes cannot be part of the Continuous Access pair.

•When pools used for a Metrocluster package are shared with other packages or applications, ensure that the pools are not over provisioned by one application impacting the high availability of the other applications.

•A Metrocluster package can have multiple pools or TP-VOL.

•Configure adequate monitoring and alerting mechanisms for the ThP pools.

Overview of Continuous Access P9000 and XP Concepts 163