Managing Serviceguard A.11.20, March 2013

To initialize a disk for CVM, log on to the master node, then use the vxdiskadm program to
initialize multiple disks, or use the vxdisksetup command to initialize one disk at a time, as in
the following example:
/usr/lib/vxvm/bin/vxdisksetup -i c4t3d4
Creating Disk Groups
Use the following steps to create disk groups.
1. Use the vxdg command to create disk groups. Use the -s option to specify shared mode, as
in the following example:
vxdg -s init logdata c0t3d2
2. Verify the configuration with the following command:
vxdg list
NAME STATE ID
logdata enabled,shared 972078742.1084.node2
3. Activate the disk group, as follows, before creating volumes:
vxdg -g logdata set activation=sw
Mirror Detachment Policies with CVM
The default CVM disk mirror detachment policy is global, which means that as soon as one node
cannot see a specific mirror copy (plex), all nodes cannot see it as well. The alternate policy is
local, which means that if one node cannot see a specific mirror copy, then CVM will deactivate
access to the volume for that node only.
The global policy is recommended, because it ensures all nodes are accessing the same current
data. If you use local, it can cause problems if one node cannot update one of the mirror copies
and the data on that copy goes stale. If any of the other nodes read from that mirror copy, they
will read stale data. This can be avoided with the global option, because all nodes will only use
the current mirror copy, so they will all read consistent data.
This policy can be reset on a disk group basis by using the vxedit command, as follows:
vxedit set diskdetpolicy=[global|local] <DiskGroupName>
NOTE: The specific commands for creating mirrored and multipath storage using CVM are
described in the HP-UX documentation for the Veritas Volume Manager, posted at http://
www.hp.com/go/hpux-core-docs.
Creating Volumes
Use the vxassist command to create volumes, as in the following example:
vxassist -g logdata make log_files 1024m
This command creates a 1024 MB volume named log_files in a disk group named logdata.
The volume can be referenced with the block device file /dev/vx/dsk/logdata/log_files
or the raw (character) device file /dev/vx/rdsk/logdata/log_files.
Verify the configuration with the following command:
vxdg list
Now deport the disk groups:
vxdg deport <disk group name>
Adding Disk Groups to the Package Configuration
Next you need to specify the CVM disk groups for each package that uses them. You do this in
the package configuration file for modular packages and in the package control script for legacy
226 Building an HA Cluster Configuration