Logical Volume Manager (LVM) - adds an extra layer between the physical disks and the file system, which allows you to resize your storage on the fly, use multiple disks, instead of one, etc.


Physical Volume:

  • Physical Volume represents the actual disk / block device.

Volume Group:

  • Volume Groups combines the collection of Logical Volumes and Physical Volumes into one administrative unit.

Logical Volume:

  • A Logical Volume is the conceptual equivalent of a disk partition in a non-LVM system.

File Systems:

  • File systems are built on top of logical volumes.

What we are doing today:

We have a disk installed on our server which is 150GB that is located on /dev/vdb, which we will manage via LVM and will be mounted under /mnt


Update and Install LVM:

$ apt update && apt upgrade -y
$ apt install lvm2 -y
$ systemctl enable lvm2-lvmetad
$ systemctl start lvm2-lvmetad

Create the Logical Volume:

Initialize the Physical Volume to be managed by LVM, then create the Volume Group, then go ahead to create the Logical Volume:

$ pvcreate /dev/vdb
$ vgcreate vg1 /dev/vdb
$ lvcreate -l 100%FREE -n vol1 vg1

Build the Linux Filesystem with ext4 and mount the volume to the /mnt partition:

$ mkfs.ext4 /dev/vg1/vol1
$ mount /dev/vg1/vol1 /mnt
$ echo '/dev/mapper/vg1-vol1 /mnt ext4 defaults,nofail 0 0' >> /etc/fstab

Other useful commands:

To list Physical Volume Info:

$ pvs
PV         VG   Fmt  Attr PSize   PFree
/dev/vdb   vg1  lvm2 a--  139.70g    0

To list Volume Group Info:

$ vgs
VG   #PV #LV #SN Attr   VSize   VFree
vg1    1   1   0 wz--n- 139.70g    0

And viewing the logical volume size from the volume group:

$ vgs -o +lv_size,lv_name
VG   #PV #LV #SN Attr   VSize   VFree LSize   LV
vg1    1   1   0 wz--n- 139.70g    0  139.70g vol1

Information about Logical Volumes:

$ lvs
LV   VG   Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
vol1 vg1  -wi-ao---- 139.70g