Veritas Storage Foundation™ for Oracle 5.0.1 Graphical User Interface Guide

About setting up a disk group
Before creating file systems for a database, set up a disk group for each database.
A disk group lets you group disks, volumes, file systems, and files that are relevant
to a single database into a logical collection for easy administration. Because you
can move a disk group and its components as a unit from one machine to another,
you can move an entire database when all the configuration objects of the database
are in one disk group. This capability is useful in a failover situation.
Disk group configuration guidelines
Follow these guidelines when setting up disk groups:
■ Only disks that are online and do not already belong to a disk group can be
used to create a new disk group.
■ Create one disk group for each database.
■ The disk group name must be unique. Name each disk group using the Oracle
database instance name specified by the environment variable $ORACLE_SID
and a dg suffix. The dg suffix helps identify the object as a disk group. Also,
each disk name must be unique within the disk group.
■ Never create database files using file systems or volumes that are not in the
same disk group.
In earlier releases of Veritas Volume Manager, a system installed with VxVM was
configured with a default disk group, rootdg, that had to contain at least one disk.
VxVM can now function without any disk group having been configured. Only
when the first disk is placed under VxVM control must a disk group be configured.
Note: Most VxVM commands require superuser or equivalent privileges.
See the “Tuning for Performance” chapter of the Veritas Storage Foundation for
Oracle Administrator's Guide.
For more about disk groups and disk group procedures, see the Veritas Enterprise
Administrator Guide.
About selecting a volume layout
Veritas Volume Manager offers a variety of layouts that allow you to configure
your database to meet performance and availability requirements. The proper
selection of volume layouts provides optimal performance for the database
workload.
33Managing your database
About setting up a disk group