VERITAS Volume Manager 3.1 Administrator's Guide

Introduction to Volume Manager
Volume Manager Conceptual Overview
Chapter 158
Volume Manager Conceptual Overview
This section describes key terms and relationships between Volume
Manager concepts. Figure 1-20, Volume Manager System Concepts,,
illustrates the terms and concepts discussed in this section.
Why You Should Use Volume Manager
Volume Manager provides enhanced data storage service by separating
the physical and logical aspects of data management. Volume Manager
enhances data storage by controlling these aspects of storage:
• space—allocation and use
• performance—by enhancing data delivery
• data availability—continuous operation and multisystem access
• device installation—centralized and optimized support
• system—multisystem support and monitoring of private/shared
systems
Volume Manager Objects
Volume Manager is a storage management subsystem that allows you to
manage physical disks as logical devices called volumes. The Volume
Manager interfaces provide enhanced data access and storage
management by using volumes. A volume is a logical device that appears
to data management systems as a physical disk partition device.
Volumes provide enhanced recovery, data availability, performance, and
storage configuration options.
A Volume Manager volume is a logical object. Volume Manager creates
other objects that you can operate, control, monitor, and query to
optimize storage management. To configure and maintain a volume for
use, Volume Manager places physical disks under its control and collects
the disk space into disk groups. A disk group is a collection of claimed
disks organized into logical volumes. Volume Manager then allocates the
space on those disks to logical volumes. See Figure 1-20, Volume
Manager System Concepts,.