Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

Consistency groups with a parallel database

The following images shows an SRDF consistency group with a parallel database such as Oracle Parallel Server (OPS).

• The production database array spans two hosts and two arrays, A and C.
• A SRDF consistency group includes R1 devices from arrays A and C.

The same consistency group definition must exist on both hosts. If enabled, Group Name Services (GNS) automatically propagates a composite group definition to the arrays and to all locally-attached hosts running the GNS daemon.

Although each production host can provide I/O to both R1 devices in the configuration, the DBMS has a distributed lock manager that ensures two hosts cannot write data to the same R1 device at the same time.

The SRDF links to two remote arrays (B and D) enable the R2 devices on those arrays to mirror the database activity on their respective R1 devices.

A typical remote configuration includes a target-side host or hosts (not shown in the illustration) to restart and access the database copy at the target site.

Figure 1 shows the SRDF daemons located on the production hosts. Dell EMC recommends that you do not run the SRDF daemon on the same control host running database applications.