Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Cascading Failover in a Continental Cluster
Data Replication Procedures
Chapter 8 381
# symrdf -g <prisymdevgrpname> est -rbcv
5. Use the following command to check the data synchronization from
the BCV/R1 devices to the R2 devices. If the “RDF Pair STATE”
column shows the state “Synchronized” for all the devices, the
copying completed.
# symrdf -g <prisymdevgrpname> query -rbcv
6. Once the copy completes, split the SRDF link between the secondary
Symmetrix and the recovery Symmetrix
# symrdf -g <prisymdevgrpname> split -rbcv
7. Incrementally establish the BCV devices in the recovery Symmetrix
as mirrors of the standard devices if they are not already established.
These BCV devices were fully established when the volume group
were created.
# symmir -f <recbcvdev_textfile> -sid <recsymid> est
The <recbcvdev_textfile> is a file that contains a list of the standard
device and BCV device pair in the recovery Symmetrix.
8. Re-establish the BCV/R1 devices in the secondary Symmetrix as
mirrors of the standard devices:
# symmir -g <prisymdevgrpname> est -rdf
Refer to the sample script prirefreshrec in the
/opt/cmcluster/toolkit/SGSRDF/cascade/Samples directory for
examples of how these commands are used. This script is designed to be
run only on a node that connects to the primary Symmetrix.
Data Refresh Procedures in the Steady State
Once the application starts writing data to the primary Symmetrix
devices, the data on the recovery Symmetrix is out of sync with the
primary data; the data is not current but consistent. The primary data
needs to periodically synchronized to the recovery Symmetrix so its data
is not too out of date. As long as the application continues writing new
data to the primary Symmetrix, the data on the recovery Symmetrix will