as write-pending to the secondary devices (R2). The data is considered committed to the R2 side devices at cycle switch time.

Figure 50 SRDF/Asynchronous Basic Functionality

Requirements for using SRDF/Asynchronous in a Metrocluster Environment

The following describes the hardware and software requirements for setting up SRDF/Asynchronous in a Metrocluster environment:

Hardware Requirements

•EMC supports SRDF/Asynchronous on Symmetrix DMX Series only. The model numbers and the supported Enginuity level are available in EMC Symmetrix SRDF Product Guide.

•SRDF/Asynchronous supports all SRDF topologies including ESCON, point-to-point and switched fabrics. Refer to the EMC Network Storage Topology Guide for details and to plan the connectivity based on your distance requirements.

Software Requirements

•EMC Solutions Enabler (requires minimum version 6.0).

•Enginuity - Refer to the Disaster Tolerant Clusters Products Compatibility and Feature Matrix, for specific version information.

•An SRDF/Asynchronous license is required to access this functionality.

For the most recent version and compatibility information, refer to the Disaster Tolerant Clusters Products Compatibility and Feature Matrix (Metrocluster/EMC SRDF – MC/SRDF).

Preparing the Cluster for SRDF/Asynchronous Data Replication

The following sections, “Metrocluster with SRDF/Asynchronous Data Replication”, and “Configuring Metrocluster with EMC SRDF using SRDF/Asynchronous” describe architectures and configurations for preparing SRDF/Asynchronous data replication.

Metrocluster SRDF Topology using SRDF/Asynchronous

Figure 51 shows the recommended and supported disaster tolerant architecture in a Metropolitan cluster, using SRDF/Asynchronous data replication. The architecture consists of two main data centers and a third location with arbitrator nodes or quorum server nodes.

Metrocluster with SRDF/Asynchronous Data Replication 291