Building Disaster Recovery Serviceguard Solutions Using Metrocluster with Continuous Access for P9000 and XP A.11.00
Creating Device Group Pairs for Multi-Target Bi-Link configuration
For a Multi-Target-Bi-Link configuration, first create the Continuous Access-Sync or
Continuous Access Journal pair between DC1 and DC2. Then create the Continuous Access
journal pair between DC1 and DC3. Use the following to create the pairs:
1. Create the Continuous Access sync or Journal device group between DC1 and DC2.
a. When using 3DC Sync/CAJ replication, create the Continuous Access Synchronous
device group pair dg12 from any node in DC1:
# paircreate –g dg12 –f <data or never> –vl –c 15
or
When using 3DC CAJ/CAJ replication, create the Continuous Access Journal
device group pair dg12 from any node in DC1:
# paircreate –g dg12 –f async –vl –c 15 –jp <Journal_id> -js
<Journal_id>
b. Wait for the PAIR state to come up for the dg12 device group.
# pairevtwait -g dg12 -t 300 -s pair
2. Create Continuous Access Journal device group pair dg13 between DC1 and DC3
from any DC1 node:
— paircreate -g dg23 -vl -f async -c 15 -jp <Journal_id> -js
<Journal_id>
NOTE: Paired devices must be of compatible sizes and types. Only OPEN-V LUNs are supported
for Three Data Center configuration.
Assigning Remote Command Devices to Journal Volumes
This step is required only when you are using Tri-Link with Delta Resync configuration. Once all
the three device groups are created, you must assign the Remote Command Devices (RCMD) to
journal volumes in all sites. These Remote Command Devices must have already been configured
as part of “Infrastructure Requirements” (page 107). In this step, the configured RCMD must be
assigned to the journal volumes in all sites. For details on assigning RCMD to journal volumes, see
the section Assigning Remote Command Devices to Mirrors” in the HP StorageWorks P9000
Continuous Access Journal Software User Guide or HP StorageWorks XP24000/XP20000
Continuous Access Journal Software User Guide available at:
http://h20000.www2.hp.com/bizsupport/TechSupport/Product.jsp?lang=en&cc=us&taskId=101&
contentType=SupportManual&docIndexId=64255&prodTypeId=18964&prodCatId=304619
This configuration step is required by the HP Storage Works 3DC replication for performing
operations on the Delta Resync pair. Whenever any Continuous Access journal device groups is
deleted using the pairsplit -S command or through P9000 or XP Remote Web Console, the
corresponding assignment of the RCMD to journal volume also gets deleted. Therefore, whenever
you recreate any device group pair using the paircreate command or through Remote Web
Console, you must reassign RCMD to journal volumes for that pair.
LVM Volume Groups Configuration
The LVM volume groups that use the application device group must be created (or imported) on
all three data centers cluster nodes. The procedure to create the LVM volume groups is similar to
that of creating volume groups for a two-site Metrocluster setup. Create all the LVM volume groups
in one of the DC1 nodes and, import all them for the rest of the three data centers cluster nodes.
Use the following procedure to create and export LVM volume groups:
NOTE: If you are using the March 2008 version or later of HP-UX 11i v3, you can skip step 1;
vgcreate (1m) will create the device file for you.
118 Designing a Three Data Center Disaster Recovery Solution