LVM Administrator's Guide

LVM Administrator's Guide

Configuration and Administration

Copyright © 2008 Red Hat, Inc.

Legal Notice

July 2008

Abstract

This book describes the LVM logical volume manager for Red Hat Enterprise Linux 5.2, including information on running LVM in a clustered environment. The content of this document is specific to the LVM2 release.

Introduction
1. About This Guide
2. Audience
3. Software Versions
4. Related Documentation
5. Feedback
6. Document Conventions
1. The LVM Logical Volume Manager
1.1. Logical Volumes
1.2. LVM Architecture Overview
1.3. Running LVM in a Cluster
1.4. Document Overview
2. LVM Components
2.1. Physical Volumes
2.1.1. LVM Physical Volume Layout
2.1.2. Multiple Partitions on a Disk
2.2. Volume Groups
2.3. LVM Logical Volumes
2.3.1. Linear Volumes
2.3.2. Striped Logical Volumes
2.3.3. Mirrored Logical Volumes
2.3.4. Snapshot Volumes
3. LVM Administration Overview
3.1. Creating LVM Volumes in a Cluster
3.2. Logical Volume Creation Overview
3.3. Growing a File System on a Logical Volume
3.4. Logical Volume Backup
3.5. Logging
4. LVM Administration with CLI Commands
4.1. Using CLI Commands
4.2. Physical Volume Administration
4.2.1. Creating Physical Volumes
4.2.2. Displaying Physical Volumes
4.2.3. Preventing Allocation on a Physical Volume
4.2.4. Resizing a Physical Volume
4.2.5. Removing Physical Volumes
4.3. Volume Group Administration
4.3.1. Creating Volume Groups
4.3.2. Adding Physical Volumes to a Volume Group
4.3.3. Displaying Volume Groups
4.3.4. Scanning Disks for Volume Groups to Build the Cache File
4.3.5. Removing Physical Volumes from a Volume Group
4.3.6. Changing the Parameters of a Volume Group
4.3.7. Activating and Deactivating Volume Groups
4.3.8. Removing Volume Groups
4.3.9. Splitting a Volume Group
4.3.10. Combining Volume Groups
4.3.11. Backing Up Volume Group Metadata
4.3.12. Renaming a Volume Group
4.3.13. Moving a Volume Group to Another System
4.3.14. Recreating a Volume Group Directory
4.4. Logical Volume Administration
4.4.1. Creating Logical Volumes
4.4.2. Persistent Device Numbers
4.4.3. Resizing Logical Volumes
4.4.4. Changing the Parameters of a Logical Volume Group
4.4.5. Renaming Logical Volumes
4.4.6. Removing Logical Volumes
4.4.7. Displaying Logical Volumes
4.4.8. Growing Logical Volumes
4.4.9. Extending a Striped Volume
4.4.10. Shrinking Logical Volumes
4.5. Creating Snapshot Volumes
4.6. Controlling LVM Device Scans with Filters
4.7. Online Data Relocation
4.8. Activating Logical Volumes on Individual Nodes in a Cluster
4.9. Customized Reporting for LVM
4.9.1. Format Control
4.9.2. Object Selection
4.9.3. Sorting LVM Reports
4.9.4. Specifying Units
5. LVM Configuration Examples
5.1. Creating an LVM Logical Volume on Three Disks
5.1.1. Creating the Physical Volumes
5.1.2. Creating the Volume Group
5.1.3. Creating the Logical Volume
5.1.4. Creating the File System
5.2. Creating a Striped Logical Volume
5.2.1. Creating the Physical Volumes
5.2.2. Creating the Volume Group
5.2.3. Creating the Logical Volume
5.2.4. Creating the File System
5.3. Splitting a Volume Group
5.3.1. Determining Free Space
5.3.2. Moving the Data
5.3.3. Splitting the Volume Group
5.3.4. Creating the New Logical Volume
5.3.5. Making a File System and Mounting the New Logical Volume
5.3.6. Activating and Mounting the Original Logical Volume
5.4. Removing a Disk from a Logical Volume
5.4.1. Moving Extents to Existing Physical Volumes
5.4.2. Moving Extents to a New Disk
6. LVM Troubleshooting
6.1. Troubleshooting Diagnostics
6.2. Displaying Information on Failed Devices
6.3. Recovering from LVM Mirror Failure
6.4. Recovering Physical Volume Metadata
6.5. Replacing a Missing Physical Volume
6.6. Removing Lost Physical Volumes from a Volume Group
6.7. Insufficient Free Extents for a Logical Volume
7. LVM Administration with the LVM GUI
A. The Device Mapper
A.1. Device Table Mappings
A.1.1. The linear Mapping Target
A.1.2. The striped Mapping Target
A.1.3. The mirror Mapping Target
A.1.4. The snapshot and snapshot-origin Mapping Targets
A.1.5. The error Mapping Target
A.1.6. The zero Mapping Target
A.1.7. The multipath Mapping Target
A.1.8. The crypt Mapping Target
A.2. The dmsetup Command
A.2.1. The dmsetup info Command
A.2.2. The dmsetup ls Command
A.2.3. The dmsetup status Command
A.2.4. The dmsetup deps Command
B. The LVM Configuration Files
B.1. The LVM Configuration Files
B.2. Sample lvm.conf File
C. LVM Object Tags
C.1. Adding and Removing Object Tags
C.2. Host Tags
C.3. Controlling Activation with Tags
D. LVM Volume Group Metadata
D.1. The Physical Volume Label
D.2. Metadata Contents
D.3. Sample Metadata
Index