Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

Consistency groups with BCV access at the target site

When an SRDF consistency group includes devices on one or more source arrays propagating production data to one or more target arrays, TF BCVs at the target site can be indirectly involved in the consistency process.

The following image shows a configuration with target-side BCVs that mirror the R2 devices:

You must split the BCV pairs at the target sites to access data on the BCVs from the target-side hosts.

The recovery sequence in a configuration that includes BCVs at the target site is the same as described in Recovering from a failed dynamic modify operation with the following exception:

At the end of the sequence, the DBMS-restartable copy of the database exists on the target R2 devices and on the BCVs if the BCVs were synchronized with the target site's R2 devices at the time the interruption occurred.

When data propagation is interrupted, the R2 devices of the suspended SRDF pairs are in a Write Disabled state. The target-side hosts cannot write to the R2 devices, thus protecting the consistent DBMS-restartable copy on the R2 devices.

You can perform disaster testing and business continuance tasks by splitting off the BCV version of the restartable copy, while maintaining an unchanged R2 copy of the database. The R2 copy can remain consistent with the R1 production database until normal SRDF mirroring between the R1 and R2 sides resumes.

This configuration allows you to split off and access the DBMS-restartable database copy on the BCVs without risking the data protection that exists on the R2 devices when propagation of data is interrupted.

To manage the BCVs from the R2 side, associate the BCVs with a single SRDF consistency group defined on the target-site host that is connected to arrays B and D.