User's Guide

# symmir -g dgname split -rdf
2. Begin to resynchronize the data from R1 to R2 devices.
# symrdf -g dgname est
3. Re-establish the BCV to R2 devices on R2 as a mirror.
# symmir -g dgname -full est
Alternatively, from node on R1 side.
# symmir -g dgname -full est -rdf
R1/R2 Swapping
This section describes how the R1/R2 swapping can be done via the Metrocluster SRDF package
and manual procedures. Each of these methods allows swapping the SRDF personality for each
device designation of a specified device group. In this situation, each source R1 device(s) becomes
a target R2 device(s), and a target R1 device(s) becomes a source R1 device(s).
R1/R2 Swapping using Metrocluster SRDF
The Metrocluster SRDF package can be configured to automatically do R1/R2 swapping upon
package failover. To enable R1/R2 swapping in the package, set the environment variable
AUTOSWAPR2 in the <package_name>_srdf.env file to 1 or 2. Since the swap is done
automatically upon package start up, the Metrocluster SRDF software will only do the swap if the
Symmetrix frames and the SRDF links between them are working properly, that is, the SRDF state
of the device group is in Synchronized state. If the failover and swap operations succeed, the
devices will have their personalities switched, and the data replication will continue from the new
R1 devices to the new R2 devices.
Prior to Metrocluster performing an R1/R2 swap, if the failover operation fails, the package will
not be automatically started. If the failover operation succeeds, but R1/R2 swapping fails, then
either the package is automatically started or fails depending on the value of the environment
variable AUTOSWAPR2.
The environment variable AUTOSWAPR2 can be set to either “1” or “2”. This will depend on whether
the package needs to be started automatically on R2, in case of R1/R2 swap failure.
If AUTOSWAPR2 is set to “1”, the package will fail to start if R1/R1 swapping fails. In this scenario
it is necessary to start the package manually by doing the swap operation. If preferred, this can
be done at a later time.
If AUTOSWAPR2 is set to “2”, the package is automatically started regardless of a R1/R2 swap
failure. In this scenario the data will not be protected remotely.
NOTE: When failing over a package with R1/R2 swapping, the package startup time will be
longer than without the swapping.
R1/R2 Swapping using Manual Procedures
It is also possible to do R1/R2 swapping manually. There are two scenarios where manual swapping
is supported by Metrocluster with EMC SRDF.
Scenario 1: In this scenario, the package failover is due to host failure or due to planned downtime
maintenance. The SRDF links and the Symmetrix frames are still up and running. Because the
package startup time will be longer if the swapping is done automatically, the user can choose
not to have the swapping done by the package and then manually execute the swapping after the
package is up and running on the R2 side. Following is the manual procedure to swap the devices
personalities and change the direction of the data replication.
On the host that connects to the R2 side, use the following steps:
Building a Metrocluster Solution with EMC SRDF 287