Installation guide
Table Of Contents
- LVM Administrator's Guide
- Table of Contents
- Introduction
- Chapter 1. The LVM Logical Volume Manager
- Chapter 2. LVM Components
- Chapter 3. LVM Administration Overview
- Chapter 4. LVM Administration with CLI Commands
- 1. Using CLI Commands
- 2. Physical Volume Administration
- 3. Volume Group Administration
- 3.1. Creating Volume Groups
- 3.2. Adding Physical Volumes to a Volume Group
- 3.3. Displaying Volume Groups
- 3.4. Scanning Disks for Volume Groups to Build the Cache File
- 3.5. Removing Physical Volumes from a Volume Group
- 3.6. Changing the Parameters of a Volume Group
- 3.7. Activating and Deactivating Volume Groups
- 3.8. Removing Volume Groups
- 3.9. Splitting a Volume Group
- 3.10. Combining Volume Groups
- 3.11. Backing Up Volume Group Metadata
- 3.12. Renaming a Volume Group
- 3.13. Moving a Volume Group to Another System
- 3.14. Recreating a Volume Group Directory
- 4. Logical Volume Administration
- 4.1. Creating Logical Volumes
- 4.2. Persistent Device Numbers
- 4.3. Resizing Logical Volumes
- 4.4. Changing the Parameters of a Logical Volume Group
- 4.5. Renaming Logical Volumes
- 4.6. Removing Logical Volumes
- 4.7. Displaying Logical Volumes
- 4.8. Growing Logical Volumes
- 4.9. Extending a Striped Volume
- 4.10. Shrinking Logical Volumes
- 5. Creating Snapshot Volumes
- 6. Controlling LVM Device Scans with Filters
- 7. Online Data Relocation
- 8. Activating Logical Volumes on Individual Nodes in a Cluster
- 9. Customized Reporting for LVM
- Chapter 5. LVM Configuration Examples
- Chapter 6. LVM Troubleshooting
- Chapter 7. LVM Administration with the LVM GUI
- Appendix A. The Device Mapper
- Appendix B. The LVM Configuration Files
- Appendix C. LVM Object Tags
- Appendix D. LVM Volume Group Metadata
- Index
Appendix B. The LVM
Configuration Files
LVM supports multiple configuration files. At system startup, the lvm.conf configuration file is
loaded from the directory specified by the environment variable LVM_SYSTEM_DIR, which is set to /
etc/lvm by default.
The lvm.conf file can specify additional configuration files to load. Settings in later files override
settings from earlier ones. To display the settings in use after loading all the configuration files,
execute the lvm dumpconfig command.
For information on loading additional configuration files, see Section 2, “Host Tags”.
1. The LVM Configuration Files
The following files are used for LVM configuration:
/etc/lvm/lvm.conf
Central configuration file read by the tools.
etc/lvm/lvm_hosttag.conf
For each host tag, an extra configuration file is read if it exists: lvm_hosttag.conf. If that file
defines new tags, then further configuration files will be appended to the list of tiles to read
in. For information on host tags, see Section 2, “Host Tags”.
In addition to the LVM configuration files, a system running LVM includes the following files that
affect LVM system setup:
/etc/lvm/.cache
Device name filter cache file (configurable).
/etc/lvm/backup/
Directory for automatic volume group metadata backups (configurable).
/etc/lvm/archive/
Directory for automatic volume group metadata archives (configurable with regard to direct-
ory path and archive history depth).
/var/lock/lvm/
In single-host configuration, lock files to prevent parallel tool runs from corrupting the
metadata; in a cluster, cluster-wide DLM is used.
2. Sample lvm.conf File
The following is a sample lvm.conf configuration file.
[root@tng3-1 lvm]# cat lvm.conf
68