User's Guide

Configuring Metrocluster with EMC SRDF using SRDF/Asynchronous Multi-Session
Consistency (MSC) Data Replication
The following sections describe the steps for building a composite group and package configuration
in a SRDF/Asynchronous MSC environment. Following are the topics discussed in this chapter:
• Building a Composite Group for SRDF/Asynchronous MSC
• Configuring a package using SRDF/Asynchronous MSC
• Setting up the RDF Daemon
Building a Composite Group for SRDF/Asynchronous MSC
To perform an operation on a composite group for SRDF/Asynchronous MSC data replication,
the composite group must be configured with devices that are SRDF/Asynchronous capable within
the RDF group. Use the following steps to create a composite 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 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
2. Create a composite group for MSC. For example, the group name 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 needs to 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
Following is a sample output of the command:
Source (R1) View Target (R2) View MODES
---------------------- ---------------- ----- --------
ST LI ST
Standard A N A
Logical Sym T R1 Inv R2 Inv K T R1 Inv R2 Inv RDF Pair
Device Dev E Tracks Tracks S Dev E Tracks Tracks MDAC STATE
------------------------ -- ------------------ ----- ------- -----
DEV001 0196 RW 0 0 RW 0012 WD 0 0 S... Synchronized
DEV002 0197 RW 0 0 RW 0013 WD 0 0 S... Synchronized
DEV003 0198 RW 0 0 RW 0014 WD 0 0 S... Synchronized
Source (R1) View Target (R2) View MODES
----------------------- ------------------ ----- ----------
Metrocluster with SRDF/Asynchronous Multi-Session Consistency Data Replication 297