Ubuntu LVM Improper Partitioning

The Problem

When installing Ubuntu Server with the LVM option in the default partitioning options, it will often only use a fraction of the actual disk space you have available. Thankfully LVM is flexible enough to extend this partition without causing any huge issues to your operating system. In this writeup, I'm gonna extend a 15G volume to a 200G volume on my Ubuntu 22.04.3 LTS VM.

user@ubuntu:~$ lsblk

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS

loop0 7:0 0 55M 1 loop /snap/core18/1880

loop1 7:1 0 55.7M 1 loop /snap/core18/2812

loop2 7:2 0 63.9M 1 loop /snap/core20/2105

loop3 7:3 0 74.1M 1 loop /snap/core22/1033

loop4 7:4 0 71.3M 1 loop /snap/lxd/16099

loop5 7:5 0 91.8M 1 loop /snap/lxd/24061

loop6 7:6 0 40.9M 1 loop /snap/snapd/20290

sda 8:0 0 200G 0 disk

├─sda1 8:1 0 1M 0 part

├─sda2 8:2 0 1G 0 part /boot

└─sda3 8:3 0 199G 0 part

└─ubuntu--vg-ubuntu--lv 253:0 0 15G 0 lvm /

sr0 11:0 1 4.5G 0 rom

user@ubuntu:~$ df -h

Filesystem Size Used Avail Use% Mounted on

tmpfs 794M 1.7M 793M 1% /run

/dev/mapper/ubuntu--vg-ubuntu--lv 15G 14G 497M 97% /

tmpfs 3.9G 0 3.9G 0% /dev/shm

tmpfs 5.0M 0 5.0M 0% /run/lock

/dev/sda2 974M 223M 684M 25% /boot

tmpfs 794M 16K 794M 1% /run/user/1000

The Fix

First, let's ensure that our physical volume is correctly sized, this command won't really do much if it is, but ts worth running just to be sure.

user@ubuntu:~$ sudo pvresize /dev/sda3

Physical volume "/dev/sda3" changed

1 physical volume(s) resized or updated / 0 physical volume(s) not resized

user@ubuntu:~$ sudo pvdisplay

--- Physical volume ---

PV Name /dev/sda3

VG Name ubuntu-vg

PV Size <199.00 GiB / not usable 16.50 KiB

Allocatable yes

PE Size 4.00 MiB

Total PE 50943

Free PE 47104

Allocated PE 3839

PV UUID cJAk5B-AR3A-PYh2-muKW-ZaOm-3T0u-Fo7VWz

Now, we need to resize the volume itself to consume 100% of the free space and not just the 15G that it's using now.

user@ubuntu:~$ sudo lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv

Size of logical volume ubuntu-vg/ubuntu-lv changed from <15.00 GiB (3839 extents) to <199.00 GiB (50943 extents).

Logical volume ubuntu-vg/ubuntu-lv successfully resized.

user@ubuntu:~$ sudo lvdisplay

--- Logical volume ---

LV Path /dev/ubuntu-vg/ubuntu-lv

LV Name ubuntu-lv

VG Name ubuntu-vg

LV UUID n55bW0-FSzX-2CGy-FB4J-8n6G-DpmA-yr2Ll6

LV Write Access read/write

LV Creation host, time ubuntu-server, 2021-07-13 22:47:18 +0000

LV Status available

# open 1

LV Size <199.00 GiB

Current LE 50943

Segments 1

Allocation inherit

Read ahead sectors auto

- currently set to 256

Block device 253:0

Now we need to go into the file system and extend it with this newfound space.

user@ubuntu:~$ sudo resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv

resize2fs 1.46.5 (30-Dec-2021)

Filesystem at /dev/mapper/ubuntu--vg-ubuntu--lv is mounted on /; on-line resizing required

old_desc_blocks = 2, new_desc_blocks = 25

The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 52165632 (4k) blocks long.

Now we can check our work.