User's Guide

Figure 51 Metrocluster Topology using SDRF/Asynchronous
Data replication can utilize any extended SAN devices that support SRDF Links, for example
DWDM, Fiber Channel over Internet Protocol, etc. However, since the network for a Serviceguard
cluster heartbeat requires a “Dark Fiber” link, it is recommended to utilize the DWDM links for
SRDF/Asynchronous data replication. This will increase data replication bandwidth and reliability
in the Metrocluster environment.
Configuring Metrocluster with EMC SRDF using SRDF/Asynchronous
The following sections, “Building a Device Group for SRDF/Asynchronous”, and “Package
Configuration using SRDF/Synchronous or SRDF/Asynchronous” describe the steps for building a
device group and package configuration in an SRDF/Asynchronous environment.
Building a Device Group for SRDF/Asynchronous
To perform an operation on a device group for SRDF/Asynchronous data replication, the device
group must be configured with all the devices that are SRDF/Asynchronous capable within the
RDF group. Use the following steps to create a device group:
1. List SRDF/Asynchronous capable devices on the source Symmetrix unit and be sure the
SRDF/Asynchronous capable devices are mapped to RDF group for use. In addition, all RDF
devices that belong to the RDF (RA) group must be configured in one device group for
SRDF/Asynchronous operation. For example, use the following command to display the devices
from RDF (RA) group number 5:
# symrdf -sid symid list -rdfa -rdfg 5
Symmetrix ID: 000187400684
Local Device View
-------------------------------------------------------------------------
STATUS MODES RDF S T A T E S
Sym RDF --------- ----- R1 Inv R2 Inv ----------------------
Dev RDev Typ:G SA RA LNK MDA Tracks Tracks Dev RDev Pair
---- ---- ------ --------- ----- ------- ------- --- ---- -------------
0196 0012 R1:5 RW RW RW S.. 0 0 RW WD Synchronized
0197 0013 R1:5 RW RW RW S.. 0 0 RW WD Synchronized
0198 0014 R1:5 RW RW RW S.. 0 0 RW WD Synchronized
0199 0015 R1:5 RW RW RW S.. 0 0 RW WD Synchronized
019A 0016 R1:5 RW RW RW S.. 0 0 RW WD Synchronized
019B 0017 R1:5 RW RW RW S.. 0 0 RW WD Synchronized
292 Building Disaster Recovery Serviceguard Solutions Using Metrocluster with EMC SRDF