Extending LVM Logical Volume (LV) in Linux – Runbook

Wed, 22 Apr 2026 11:24:42 +0530

Purpose
Extend disk space on a Linux system using LVM without downtime.

Applies to
Systems using LVM (Logical Volume Manager)

Problem

Filesystem (e.g. /, /var) is running out of space and needs to be extended.

Step 1 — Check Current Disk Usage

Code:
df -h

Output:

Code:
/dev/mapper/rootvg-varlv    14G  13G  1.4G  91% /var

Outcome:

Identify which mount point is full (e.g /var)
This determines which LV needs extension

Step 2 — Verify LVM Setup (Build Context for Extension)

1. Map LV to Mount Point

Code:
lsblk

Output :

Code:
NAME              MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS

sda                8:0    0  256G  0 disk

├─sda4              8:4    0 63.3G  0 part

  ├─rootvg-varlv  253:3    0  14G  0 lvm  /var

└─sda5              8:5    0  100G  0 part

  ├─rootvg-varlv  253:3    0  14G  0 lvm  /var

Insight:

Identifies which LV is mounted where
Confirms LVM usage (TYPE = lvm)

2. Identify Target LV

Code:
lvs -o lv_name,vg_name,lv_path

Output:

Code:
LV    VG    Path

varlv  rootvg /dev/rootvg/varlv

Insight:

Confirms exact LV name to extend (e.g varlv)
Provides correct device path required for lvextend (e.g /dev/rootvg/varlv)

3. Check Available Space in VG

Code:
vgs

Output:

Code:
VG    #PV #LV #SN Attr  VSize    VFree

rootvg  2  5  0 wz--n- <163.31g 316.00m

Insight:

Determines if extension is possible

Interpretation:

VFree > 0
→ Extend directly
VFree = 0
→ Add disk first

4. Check Underlying Disks

Code:
pvs

Code:
PV        VG    Fmt  Attr PSize    PFree

/dev/sda4  rootvg lvm2 a--  63.31g    0

/dev/sda5  rootvg lvm2 a--  <100.00g 316.00m

Insight:

Shows disks backing the VG
Confirms whether storage is already fully utilized

Step 2 Outcome (What we now know)

Which LV to extend (varlv)
Its mount point (/var) and exact path (/dev/rootvg/varlv)
Whether free space exists in VG
Which disks are backing LVM

Decision Point

Case A: VG has free space
→ Extend LV directly

Case B: No free space
→ Add disk / extend storage first

Case A — Extend LV (VG has free space)

Step 3 — Extend Logical Volume

Code:
lvextend -L +316M /dev/rootvg/varlv

-L → size in GB/MB

OR use all free space:

Code:
lvextend -l +100%FREE /dev/rootvg/varlv

-l → extents / percentage

Outcome:

Code:
Size of logical volume rootvg/varlv changed from 14.00 GiB (3584 extents) to <14.31 GiB (3663 extents).

Logical volume rootvg/varlv successfully resized.

LV size increases
Filesystem unchanged (IMPORTANT)

Step 4 — Resize Filesystem

Check filesystem:

Code:
lsblk -f

For ext4:

Code:
resize2fs /dev/rootvg/varlv

For xfs:

Code:
xfs_growfs /var

Outcome:

Filesystem expands to use new space

Step 5 — Verify

Code:
df -h

Case B — No Free Space in VG

Step 3 — Add New Disk (Cloud / VM level)

Add a new disk from your cloud provider / hypervisor (e.g. AWS, Azure, VMware)
Example: New disk appears as /dev/sdb
Verify Disk is Added

Code:
lsblk
New disk should be visible (e.g. /dev/sdb)

Step 4 — Create PV

Code:
pvcreate /dev/sdb

Step 5 — Extend VG

Code:
vgextend rootvg /dev/sdb

Step 6 — Extend LV

Code:
lvextend -l +100%FREE /dev/rootvg/varlv

Step 7 — Resize Filesystem

Code:
xfs_growfs /var

# OR

Code:
resize2fs /dev/rootvg/varlv

Step 8 — Verify

Code:
df -h

Additional Note — Expanding Existing Disk

If the same disk is increased in size (no new disk added):

Code:
growpart /dev/sda 4

Code:
pvresize /dev/sda4

Outcome:

growpart → expands the partition
pvresize → makes new space available to LVM

You can now proceed with lvextend

Common Mistakes

Extending LV but not resizing filesystem
Using wrong filesystem command (resize2fs vs xfs_growfs)
Not checking vgs before starting
Using wrong device path
Confusing disk (/dev/sdb) with LV (/dev/rootvg/varlv)

Key Concepts and Takeaways

PV (Physical Volume) → Disk (/dev/sda4)
VG (Volume Group) → Storage pool (rootvg)
LV (Logical Volume) → Usable volume (/var)

Flow:
Disk → PV → VG → LV → Filesystem

Extension = LV resize + filesystem resize
vgs decides your approach (direct vs add disk)
LVM allows online resizing (no downtime)

Precautions

Take backup before changes
Double-check device names
Run carefully on production

Upgrade Guide: Ubuntu 22.04 LTS → 24.04.4 LTS (Noble Numbat)

Tue, 07 Apr 2026 17:01:54 +0530

Purpose: Upgrade Ubuntu systems from 22.04 LTS to 24.04 LTS with full step-by-step procedure (including what appears on screen during upgrade)
Document Type: Operational Runbook

? Step 1 — Check Current Version

Code:
cat /etc/os-release

? Confirm:

VERSION="22.04 LTS"
CODENAME=jammy

? Step 2 — Update Current System

Code:
sudo apt update && sudo apt upgrade

? During this step:

You may see package list fetching
If prompted:
- Press Y to continue

? Step 3 — Install update-manager-core

Code:
sudo apt install update-manager-core

? If prompted:

Press Y → continue installation

Edit Upgrade Configuration

Code:
sudo nano /etc/update-manager/release-upgrades

Find:

Code:
Prompt=normal

Change to:

Code:
Prompt=lts

? Save:

CTRL + X
Press Y
Press ENTER

⚙️ Step 4 — Prepare System (dist-upgrade)

Code:
sudo apt dist-upgrade

? During this step:

System may install/remove dependencies
If prompted:
- Press Y to continue

? Step 5 — Reboot System

Code:
sudo reboot

? Step 6 — Run Release Upgrade

Code:
sudo do-release-upgrade

? You will now see multiple interactive prompts:
1. Checking for new release

System checks availability of Ubuntu 24.04

2. Upgrade Summary Screen

Shows:
- Packages to install
- Packages to upgrade
- Packages to remove
Prompt:
- "Do you want to start the upgrade?"
- Press Y

3. Download Packages

Shows download progress
No input required unless interrupted

4. Configuration File Prompts
You may see:

"A new version of config file is available"

Options:

Press Y → install new version
Press N → keep existing version

? Recommendation:

Use N if unsure (safer)

5. Service Restart Prompt

"Restart services during package upgrades without asking?"

Options:

Select Yes → recommended

6. Obsolete Packages Prompt

"Remove obsolete packages?"

Options:

Press Y → clean system

7. Kernel/GRUB Prompt (if appears)

Keep current selection unless you know otherwise

8. Final Prompt

"System upgrade is complete. Restart required"
Press Y

? Step 7 — Final Reboot
? System reboots automatically or asks:

Press Y to reboot

✅ Step 8 — Verify Upgrade

Code:
cat /etc/os-release

Code:
lsb_release -a

? Confirm:

VERSION="24.04.4 LTS"
CODENAME=noble

? Optional Cleanup

Code:
sudo apt autoremove -y

⚠️ Important Notes

Always take backup before upgrade
Ensure stable internet connection
Do not interrupt upgrade
Recommended downtime window
Ensure at least 5–10 GB free disk space

? Troubleshooting
If upgrade not detected:

Code:
sudo do-release-upgrade -d

If upgrade fails midway:

Code:
sudo dpkg --configure -a

sudo apt -f install

DevOps Discussion Forum - Linux

Extending LVM Logical Volume (LV) in Linux – Runbook

Upgrade Guide: Ubuntu 22.04 LTS → 24.04.4 LTS (Noble Numbat)