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 -Scommand 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