Designing Disaster Recovery Clusters using Metroclusters and Continentalclusters, Reprinted October 2011 (5900-1881)
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 429). 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.
1. Define the appropriate Volume Groups on all cluster nodes that run the application package.
# mkdir /dev/vgxx
# mknod /dev/vgxx/group c 64 0xnn0000
Where the VG name and minor number nn are unique for each volume group defined in the
node.
2. Create the Volume Group only on one node in primary data center (DC1). Use the following
commands:
# pvcreate -f /dev/rdisk/disk12
# vgcreate /dev/vgname /dev/dsk/disk12
NOTE: From HP-UX 11i v3 onwards, HP recommends that you use agile DSF naming model
for mass storage devices. For more information on the agile view, see the section About Device
File Names (Device Special Files) in the latest version of Managing Serviceguard document
available at http://www.hp.com/go/hpux-serviceguard-docs.
3. Create the logical volume(s) for the volume group on the node.
# lvcreate -L XXXX /dev/vgname
xxxx indicates size in MB.
4. Create the filesystem:
# newfs -F vxfs /dev/vgname/rlvol
5. Export the Volume Groups on the node without removing the special device files:
# vgchange -a n <vgname>
440 Designing a Three Data Center Disaster Recovery Solution