Veritas Storage Foundation Intelligent Storage Provisioning 5.0 AdministratorÆs Guide, HP-UX 11i v3, First Edition, May 2008

42 Understanding ISP
About ISP concepts
About storage layout rules
Storage layout rules specify how storage is used to create volumes. The
following are examples of storage layout rules:
For example, the following rule specifies that a volume can be created using
parity to provide data redundancy:
parity true
About volume templates
A volume template (or template for short) is a meaningful collection of rules
that provide a capability. A template can specify one or more capabilities that a
volume created using the template may have, and consists of a collection of
storage selection and layout rules. For example, a template may allow you to
create a volume that is able to tolerate the failure of a certain number of
controllers, or that has a certain number of copies of the volume data.
When creating a volume, it is easier to specify its desired capabilities than to
specify the precise layout of the volume on the available storage. ISP selects the
appropriate templates and uses them to create a volume with the desired
capabilities.
If you specify parameter values for a volume’s capabilities, the rules that are
defined within the chosen template use these values when selecting and laying
out storage. If not specified, the default parameter values for a volume’s
capabilities are assumed by the template.
Rule Description
log Specifies the type of log and its degree of redundancy.
mirror Specifies how many mirrors a volume should have.
parity Specifies whether redundancy is provided by using parity.
stripe Specifies how many columns a volume should have.
striped Specifies whether a volume is striped.