Building Disaster Recovery Serviceguard Solutions Using Metrocluster with EMC SRDF

Building a composite group for SRDF/Asynchronous MSC
To perform an operation on a consistency group for SRDF/Asynchronous MSC data replication,
the composite group must be configured with devices that are SRDF/Asynchronous capable within
the RDF group.
To create a composite group:
1. List SRDF/Asynchronous capable devices on the source Symmetrix unit and ensure that the
SRDF/Asynchronous capable devices are mapped to RDF group for use. For example, use
the following command to display the devices from RDF (RA) group number 2:
# symrdf -sid <symmid> list -rdfa -rdfg 2
Symmetrix ID: 000192603928
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 MDATE Tracks Tracks Dev RDev Pair
---- ---- -------- --------- ----- ------- ------- --- ---- -------------
80A4 0340 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A5 0341 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A6 0342 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A7 0343 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A8 0344 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A9 0345 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80AA 0346 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
2. Create a composite group for MSC. Assume the group name as MSCcg.
On R1 site, run the following command:
# symcg create MSCcg -type RDF1 –rdf_consistency
On R2 site, run the following command:
# symcg create MSCcg -type RDF2 –rdf_consistency
3. All devices from RDF (RA) groups configuration are added to the composite group for
SRDF/Asynchronous MSC operation. For example, the RDF groups 6 and 7 are added to the
composite group MSCcg for SRDF/Asynchronous MSC operation.
# symcg -cg MSCcg -rdfg 6 addall pd
# symcg -cg MSCcg –rdfg 7 addall pd
4. Repeat the steps 1-3 on each host that must run Serviceguard packages.
5. Query the composite group MSCcg to display the R1-to-R2 setup and the state of the
SRDF/Asynchronous device pairs.
# symrdf -cg MSCcg query -rdfa
6. Set the composite group to Asynchronous mode.
# symrdf -cg MSCcg set mode async
7. Enable consistency protection to ensure data consistency on R2 side for the SRDF/Asynchronous
devices in the composite group.
# symrdf -cg MSCcg enable
8. If the SRDF pairs are not in a consistent state at this point, synchronize the data on the R2 side
from the R1 side using the following command. The device state will be SyncInProg until it
reaches the consistent status.
# symrdf -cg MSCcg establish
# symrdf -cg MSCcg query -rdfa
Setting up M by N configurations 25