VERITAS Storage Foundation 4.1 Oracle Administrator's Guide

Chapter 1, VERITAS Storage Foundation for Oracle
Prerelease 8 September 2005, 8:54am VERITAS Volume Manager
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◆ Storage Expert—helps diagnose configuration problems with VxVM.
◆ Cluster Volume Manager (CVM)—separately licensed, optional feature that allows you to use
VxVM in a cluster environment.
◆ VERITAS FlashSnap Agent for Symmetrix—separately licensed, optional feature that includes
a set of commands that allows you to use EMC TimeFinder in conjunction with VxVM disk
groups and volumes that have been created on Symmetrix standard devices.
◆ VERITAS Volume Replicator (VVR)—separately licensed, optional feature that provides data
replication for disaster recovery planning.
◆ Free space pool management—simplifies administration and provides flexible use of available
hardware.
◆ Online administration—allows configuration changes without system or database down time.
The following sections provide brief overviews of VxVM concepts and features that are relevant to
database administration. The information and examples presented in the remainder of this guide
assume that you are using VERITAS Volume Manager. For a more detailed description of VxVM
and its features, refer to the VERITAS Volume Manager Administrator’s Guide.
Volumes
A volume is a virtual disk device that appears to applications, databases, and file systems like a
physical disk partition without the physical limitations of a disk partition. A volume consists of one
or more plexes, each holding a copy of the selected data in the volume. Due to its virtual nature, a
volume is not restricted to a particular disk or a specific area of a disk. For example, a volume can
span multiple disks and can be used to create a large file system.
Volumes consist of other virtual objects that can be manipulated to change the volume’s
configuration. Volumes and their virtual components are referred to as Volume Manager objects.
You can manipulate VERITAS Volume Manager objects in a variety of ways to optimize
performance, provide redundancy of data, and perform backups or other administrative tasks on
one or more physical disks without interrupting applications. As a result, data availability and disk
subsystem throughput are improved.
You can change the configuration of a volume without causing disruption to databases or file
systems that are using the volume. For example, you can mirror a volume on separate disks or
move the volume to use different disk storage.
Disk Groups
A disk group is a collection of disks that share a common configuration (for example, configuration
objects that belong to a single database). We recommend creating one disk group for each database.