In the world of UNIX storage management, there are two primary leaders: IBM

and Veritas. Both companies offer products that help UNIX system administrators

manage storage in very flexible methods in comparison to older UNIX

implementations. IBM offers the Logical Volume Manager (LVM) as part of its

Advanced Interactive Executive (AIX) operating system. The LVM is built into the

base operating system and is provided as part of the base AIX installation. Veritas

offers the Veritas Volume Manager (VxVM) which is either packaged as a

standalone add-on or part of a larger package such as the Veritas On-Line Storage

Manager. VxVM is designed to be an additional software package added to a

UNIX operating system, most notably the Solaris operating system by Sun

Microsystems, Inc.

Introduction

Terminology

Limitations

Volume Groups

Physical Volumes in Volume Groups

Physical Partitions per Volume Group

Logical Volumes per Volume Group

Logical Partitions per Logical Volume

Mirrored Copies of a Logical Volume

Functional Differences

Software RAID Levels

Mirrored Read Policy

Hot Spot Management

Read/Write Resynchronization

Online Backup of File Systems

Snapshot Backup of File Systems

Quick Resynchronization of Changed Partitions After Backup .

Migration of Data with Active Volumes

Transparent Data Stream Switch After Mirrored Disks Fail

Operation in a Multinode Concurrent Configuration

Commands to Replace Dead or Failing Drives

Hot Spare, Standby Disks

Commands

Special Notices