Building Disaster Recovery Serviceguard Solutions Using Metrocluster with EMC SRDF

Table 1 Mapping for a 4 node Cluster connected to 2 Symmetrix arrays (continued)
Nodes 4 /dev/rdsk
device file name
Node 3 /dev/rdsk
device file name
Node 2 /dev/rdsk
device file name
Node 1 /dev/rdsk
device file name
Symmetrix ID,
device #, and type
R2Type
c3t0d250ID
c4t3d2012Dev#
R1Type
c0t15d095ID
c0t15d0040Dev#
GKType
c3t15d150ID
c5t15d1041Dev#
GKType
c4t3d295ID
c4t3d2028Dev#
n/an/aBCVType
NOTE: The Symmetrix device number may be the same or different in each of the Symmetrix
units for the same logical device. In other words, the device number for the logical device on the
R1 side of the SRDF link may be different from the device number for the logical device on the R2
side of the SRDF link.
The Symmetrix logical device numbers in these examples were configured to be the same number
so the cluster is easier to manage. If you are reconfiguring an existing cluster, the Dev and RDev
devices will probably not be the same number.
When determining the configuration for the Symmetrix devices for a new installation, HP
recommends using the same Symmetrix device number for both the R1 and R2 devices. HP also
recommends that the same target and LUN number be configured for all the nodes that have access
to the same Symmetrix logical device.
Setting up a 1 by 1 configuration
The most common Symmetrix configuration used with Metrocluster with EMC SRDF is a 1 by 1
configuration in which there is a single Symmetrix frame at each Data Center. This section describes
how to set up this configuration using EMC Solutions Enabler and HP-UX commands. It is assumed
the Symmetrix CLI database is already set up on each node, as described in the previous section
“Preparing the Cluster for data replication.”
Figure 3, shows a basic 1 by 1 configuration which is a graphical view of the data in Table 1.
Setting up a 1 by 1 configuration 15