Setting up M by N Configurations

Creating Symmetrix Device Groups

For each node on the R1 side (node1 and node2), create the device groups as follows. You have to create two device groups because device groups do not span frames.

	NOTE: In a 1 by 2 or 2 by 1 configuration, on either the R1 or R2 side, whichever side has the one Symmetrix frame, a minimum of two device groups is required. The rule of thumb is that you need one device group per RDF group (RA group), even if you have only one frame on that side. The following examples are based on the 2 by 2 configuration shown in Figure 4-18 “Devices and Symmetrix Units in M by N Configurations”.

Create device groups using the following commands on each node on the R1 side:

# symdg -type RDF1 create dgoraA

# symdg -type RDF1 create dgoraB

For each node on the R2 side (node3 and node4), create the device groups as follows. Note that you have to create two device groups because device groups do not span frames. Do the following on each node on the R2 side:

# symdg -type RDF2 create dgoraA

# symdg -type RDF2 create dgoraB

For each node on the R1 side (node1 and node2), assign the R1 devices to the device groups as follows:

# symld -sid 638 -g dgoraA add dev 00C

# symld -sid 638 -g dgoraA add dev 00D

# symld -sid 130 -g dgoraB add dev 010

# symld -sid 130 -g dgoraB add dev 011

For each node on the R2 side (node3 and node4), assign the R2 devices to the device groups as follows:

# symld -sid 021 -g dgoraA add dev 018

# symld -sid 021 -g dgoraA add dev 019

# symld -sid 363 -g dgoraB add dev 050

# symld -sid 363 -g dgoraB add dev 051

On each node on the R2 side (node3 and node4), associate the local BCV devices to the R2 device group:

# symbcv -g dgoraA add dev 01A

# symbcv -g dgoraA add dev 01B

# symbcv -d dgoraB add dev 052

# symbcv -d dgoraB add dev 053

To manage the BCV devices from the R1 side, you need to associate the BCV devices with the device groups that are configured on the R1 side. Use the following commands on hosts directly connected to the R1 Symmetrix:

# symbcv -g dgoraA associate dev 01A -rdf

# symbcv -g dgoraA associate dev 01B -rdf

# symbcv -g dgoraB associate dev 052 -rdf

# symbcv -g dgoraB associate dev 053 -rdf

Now establish the BCV devices using the following commands from the R2 side:

# symmir -g dgoraA -full est

# symmir -g dgoraB -full est

Alternatively, you can establish the BCV devices with the following commands from the R1 side:

# symmir -g dgoraA -full est -rdf

# symmir -g dgoraB -full est -rdf

Configuring Gatekeeper Devices

You need a gatekeeper device for each device group in the consistency group that will be built in a later step. Use the following commands on all nodes on the R1 side to define gatekeepers and associate them with device groups:

# symgate -sid 638 define dev 010

# symgate -sid 130 define dev 009

# symgate -sid 638 -g dgoraA associate dev 010

# symgate -sid 130 -g dgoraB associate dev 009

Use the following commands on all nodes on the R2 side to define gatekeepers and associate them with device groups:

# symgate -sid 021 define dev 002

# symgate -sid 363 define dev 00B

# symgate -sid 021 -g dgoraA associate dev 002

# symgate -sid 363 -g dgoraB associate dev 00B

Defining the Consistency Groups

To configure consistency groups for use with EMC/SRDF, you first create device groups and gatekeeper groups as described in previous sections. Then you create the consistency groups and add the devices to them as well.

	NOTE: Each package requires its own unique consistency group name.

Use the following steps for each package:

Creating Volume Groups

The following procedures assume you are creating volume groups for a cluster with a 2 by 2 Symmetrix configuration like that of Figure 4-18 “Devices and Symmetrix Units in M by N Configurations”. Use the following steps on node1:

On node2, node3, and node4, perform the following steps: