Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Understanding VERITAS Volume Manager

VERITAS Volume Manager (VxVM) is a storage management subsystem that allows you

to manage physical disks as logical devices called volumes. A volume is a logical device

that appears to data management systems as a physical disk.

VxVM provides easy-to-use online disk storage management for computing

environments and Storage Area Network (SAN) environments. Through support of

Redundant Array of Independent Disks (RAID), VxVM protects against disk and

hardware failure. Additionally, VxVM provides features that enable fault tolerance and

fast recovery from disk failure.

VxVM overcomes physical restrictions imposed by hardware disk devices by providing a

logical volume management layer. This allows volumes to span multiple disks.

VxVM provides the tools to improve performance and ensure data availability and

integrity. VxVM also dynamically configures disk storage while the system is active.

The following sections of this chapter explain fundamental concepts of VxVM:

◆ How VxVM Handles Storage Management

◆ Physical Objects—Physical Disks

◆ Virtual Objects

◆ Volume Layouts in VxVM

The following sections introduce you to advanced features of VxVM:

◆ Online Relayout

◆ Volume Resynchronization

◆ Dirty Region Logging (DRL)

◆ SmartSync Recovery Accelerator

◆ Vol ume S napshots

◆ FastResync

◆ Hot-Relocation