VERITAS Storage Foundation 4.1 Intelligent Storage Provisioning Administrator's Guide

Creating Volumes
48 VERITAS Storage Foundation ISP Administrator’s Guide
◆ If you specify rules, capabilities and templates, ISP selects the appropriate templates from
those specified that conform to the desired capabilities, and that adhere to the specified rules in
addition to the rules in those templates.
Note Refer to “Using Capabilities, Templates and Rules” on page 113 for more information.
Finally, you can create volumes by specifying user templates that you have set up with the required
redundancy, fault tolerance, or performance capabilities for the applications that you run at your
site. See “Creating and Modifying User Templates” on page 107 for more information.
Creating Volumes by Specifying Capabilities
A capability is a high-level description of a volume, for example, DataMirroring, Striping
or PrefabricatedRaid5. ISP automatically selects a suitable template from those that provide
the desired capability. As such, this is the most abstract way of creating volumes using vxvoladm
as it requires the least specification by you. You can customize a capability by specifying values for
any variable parameters that it defines.
For a list of predefined capabilities that are supported, see “Capabilities” on page 165. The
following sections provide some examples of creating volumes with these capabilities.
Creating a Mirrored Volume
The following command creates a 1-gigabyte volume with the default number of 2 mirrors:
# vxvoladm -g mydg make mir2vol 1g capability=’DataMirroring’ \
init=active
The init=active attribute makes the volume immediately available for use without attempting
to synchronize its empty plexes.
The following command creates a 1-gigabyte volume with 3 mirrors:
# vxvoladm -g mydg make mir3vol 1g \
capability=’DataMirroring(nmirs=3)’ init=active
Creating a Mirrored Volume with Mirrors on Separate Enclosures
The following command creates a 2-gigabyte mirrored volume with 2 mirrors, and with the mirrors
located on separate enclosures:
# vxvoladm -g mydg make strpvol 2g capability=’DataMirroring,\
MirrorsOnSeparateComponents’
Such a volume tolerates the failure of one enclosure and provides greater reliability. Such a
capability can be combined with multipathing to provide resilience against the failure of one of the
paths to an enclosure: