Chapter 6. LVM Configuration Examples

This chapter provides some basic LVM configuration examples.

6.1. Creating an LVM Logical Volume on Three Disks

This example creates an LVM logical volume called new_logical_volume that consists of the disks at /dev/sda1, /dev/sdb1, and /dev/sdc1.

6.1.1. Creating the Physical Volumes

To use disks in a volume group, you label them as LVM physical volumes.

Warning

This command destroys any data on /dev/sda1, /dev/sdb1, and /dev/sdc1.
# pvcreate /dev/sda1 /dev/sdb1 /dev/sdc1
  Physical volume "/dev/sda1" successfully created
  Physical volume "/dev/sdb1" successfully created
  Physical volume "/dev/sdc1" successfully created

6.1.2. Creating the Volume Group

The following command creates the volume group new_vol_group.
# vgcreate new_vol_group /dev/sda1 /dev/sdb1 /dev/sdc1
  Volume group "new_vol_group" successfully created
You can use the vgs command to display the attributes of the new volume group.
# vgs
  VG            #PV #LV #SN Attr   VSize  VFree
  new_vol_group   3   0   0 wz--n- 51.45G 51.45G

6.1.3. Creating the Logical Volume

The following command creates the logical volume new_logical_volume from the volume group new_vol_group. This example creates a logical volume that uses 2GB of the volume group.
# lvcreate -L2G -n new_logical_volume new_vol_group
  Logical volume "new_logical_volume" created

6.1.4. Creating the File System

The following command creates a GFS2 file system on the logical volume.
# mkfs.gfs2 -plock_nolock -j 1 /dev/new_vol_group/new_logical_volume
This will destroy any data on /dev/new_vol_group/new_logical_volume.

Are you sure you want to proceed? [y/n] y

Device:                    /dev/new_vol_group/new_logical_volume
Blocksize:                 4096
Filesystem Size:           491460
Journals:                  1
Resource Groups:           8
Locking Protocol:          lock_nolock
Lock Table:

Syncing...
All Done
The following commands mount the logical volume and report the file system disk space usage.
# mount /dev/new_vol_group/new_logical_volume /mnt
[root@tng3-1 ~]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/new_vol_group/new_logical_volume
                       1965840        20   1965820   1% /mnt