HP Serviceguard Metrocluster with EMC SRDF for Linux B.01.00.00

NOTE: This important step must be carried out on every node.

4. Establish the BCV devices in the secondary Symmetrix as a mirror of the standard device.

From either node3 or node4, run the following commands:

# symmir -cg <Consistency Group Name> -full establish

Alternatively, from either node1 or node2, run the following command:

# symmir -cg <Consistency Group Name> -full establish -rdf

Configuring SRDF/Asynchronous Multi-Session Consistency (MSC) data replication

In order to provide a consistent, restartable local copy of data spanning across two local Symmetrix

volumes, a composite group is configured. A composite group is similar to device group but can

contain devices spanning across multiple Symmetrix arrays and multiple RDF(RA) groups. An SRDF

consistency group is a composite group with special properties to allow SRDF devices in separate

SRDF groups to maintain dependent write order consistency. The following sections describe the

steps for building a consistency group in a SRDF/Asynchronous MSC environment

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 <Symmetrix ID> 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 <Multi-session Consistency Group Name> -type RDF1

–rdf_consistency

On R2 site, run the following command:

# symcg create <Multi-session Consistency Group Name> -type RDF2

–rdf_consistency

Setting up M by N configurations 21