---
title: lsblk — inspect block device structure
date: 2026-10-18
time: 12:00
model: admin
category: programs
author_type: human
summary: Command that displays disks, partitions, mount points, and sizes in a tree format.
tags: program, File and disk management, lsblk
---

**💬 "lsblk command"**

lsblk shows the disk and partition structure attached to the server in a tree. It is an essential check before adding or mounting disks.

While df shows the file system perspective, lsblk shows the **device perspective**.

- **Concept**: Displays block devices (disks, partitions, LVM volumes) and mount points in a hierarchy.
- **NAME**: Device name. Formats such as `vda`, `vda1`, `nvme0n1p1`.
- **SIZE**: Device capacity.
- **MOUNTPOINT**: Mounted path. If empty, the device is not mounted.
## Commonly used options

| Option | Description |
| --- | --- |
| -f | Displays file system type, label, and UUID |
| -o <column list> | Output only the specified columns |
| -p | Displays device names with the full path (/dev/...) |
| -d | Displays only disks, not partitions |

## Three essential command combinations

- `lsblk -f` — Check file system type and mount status
- `lsblk -o NAME,SIZE,TYPE,MOUNTPOINT` — View only the columns you need
- `lsblk -f /dev/vdb` — Check partitions/filesystems on a specific disk
**💬 "Give me an example of isolating a problem server with this command"**

This is a step-by-step summary of situations you often encounter on live servers.

### Step 1 · Check the overall device structure

Check disks, partitions, and mount status.

```
lsblk -f
```

### Step 2 · Choose a new disk

Find a device with an empty mount point.

```
lsblk -o NAME,SIZE,TYPE,MOUNTPOINT
```

### Step 3 · Verify after mounting

After creating a filesystem and mounting it, check again.

```
lsblk -f /dev/vdb
```

## In practice, this is how it's used

### 1. Adding a disk

**Situation** — You added a volume in the cloud, but it doesn't appear yet.

```
lsblk -o NAME,SIZE,TYPE,MOUNTPOINT
```

**Result** — If a new device (vdb) appears without a MOUNTPOINT, it needs to be mounted.

**Point** — Proceed in this order: check device → create filesystem → register in /etc/fstab.

### 2. Checking for missing mounts

**Situation** — After a reboot, /data appears empty.

```
lsblk -f && grep /data /etc/fstab
```

**Result** — If the device exists but is not mounted, check the fstab configuration or mount failure.

**Point** — For partitions not shown by df, first check with lsblk whether the device itself is recognized.

## Things to watch out for

- Creating a filesystem on an unmounted device can destroy existing data. Always double-check the device name.
- In LVM environments, physical volumes and logical volumes are shown together, which can make the structure complex. Use -o to view only the items you need.
- Device names (vda/vdb) can change depending on boot order, so use UUIDs in fstab.
## Actual command output

This is the result of checking disks, partitions, and mount points (including vdc, which is not mounted).

![lsblk command output: block device structure](https://games.aidebatehub.com/assets/lsblk-demo.png)

Production server

---
Source (HTML): https://games.aidebatehub.com/programs/linux/filesystem/lsblk.html
This file is an auto-generated Markdown twin of the DevHub document.