Chapter 5. LVM Configuration Examples

This chapter provides some basic LVM configuration examples.

5.1. Creating an LVM Logical Volume on Three Disks

This example procedure creates an LVM logical volume called new_logical_volume that consists of the disks at /dev/sda1, /dev/sdb1, and /dev/sdc1.
  1. To use disks in a volume group, label them as LVM physical volumes with the pvcreate command.

    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
    
  2. Create the a volume group that consists of the LVM physical volumes you have created. 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
    
  3. Create the logical volume from the volume group you have created. 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 2 gigabytes of the volume group.
    # lvcreate -L 2 G -n new_logical_volume new_vol_group
      Logical volume "new_logical_volume" created
    
  4. Create a file system on the logical volume. The following command creates a GFS2 file system on the logical volume.
    # mkfs.gfs2 -p lock_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
    # df
    Filesystem           1K-blocks      Used Available Use% Mounted on
    /dev/new_vol_group/new_logical_volume
                           1965840        20   1965820   1% /mnt