HP Serviceguard Metrocluster with EMC SRDF for Linux B.01.00.00
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.
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 for Linux 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 Linux commands. It
is assumed that the Solutions Enabler database is already set up on each node.
Figure 3, shows a basic 1 by 1 configuration which is a graphical view of the data in Table 1.
Figure 3 Mapping Linux device file names to Symmetrix units
Symmetrix ID 95
SRDF
Node 1
Data Center A Data Center B
Node 2
Node 3
Node 4
R1
R2
GK
BCV
Symmetrix ID 50
R2
R1
GK
1. /dev/sda
2. /dev/sdb
3. /dev/sdc
4. /dev/sdd
5. /dev/sdc
6. /dev/sdd
7. /dev/sda
8. /dev/sdb
9. /dev/sdb
10. /dev/sda
11. /dev/sdc
12. /dev/sdd
13. /dev/sdb
14. /dev/sde
1
2
3
4
5
6
7
8
9
12
13
14
10
11
Creating Symmetrix device groups
Configuring a device group for SRDF/synchronous
A single Symmetrix device group must be defined for each package on each node that is connected
to the Symmetrix. You must perform the following procedure on each node that might potentially
run the package:
1. Use the symdg command, create an R1 and an R2 device group for each package.
# symdg create -type RDF1 <Device Group Name>
Run this command on nodes attached to the R1 side.
12 Configuring an application in a Metrocluster solution