---
title: How to mount a Block Storage volume to an Instance
description: This guide explains how to mount a Block Storage volume to your Scaleway Instance before being able to use it.
tags: mount link volume disk instance
dates:
  validation: 2025-10-10
  posted: 2025-10-10
---
import Requirements from '@macros/iam/requirements.mdx'

- A Scaleway account logged into the [console](https://console.scaleway.com)
- [Owner](/iam/concepts/#owner) status or [IAM permissions](/iam/concepts/#permission) allowing you to perform actions in the intended Organization
- An [Instance](/instances/concepts/#instance)
- [Attached](/block-storage/how-to/attach-a-volume/) an additional Block Storage volume to your Instance

## Mounting and using a Block Storage volume

In order to mount and use your Block Storage volume, you need to connect to the Instance it is attached to, via SSH.
Then, check that the volume is available, format it, and mount it following the instructions below.

### Verifying device availability

1. Connect to your Instance with `ssh`.
    ```
    ssh root@<your_instance_ip>
    ```
2. Use the `lsblk` command to confirm that your block volume is available:
    ```
    lsblk
    ```

   You should see an output similar to the following. The root Block volume `sda`, contains your OS. The Block volume named `sdb` is the one we will be mounting to the Instance.

    ```sh no-copy
    root@scw-festive-agnesi:~# lsblk
    NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
    sda       8:0    0 18.6G  0 disk
    ├─sda1    8:1    0 18.5G  0 part /
    ├─sda14   8:14   0    4M  0 part
    └─sda15   8:15   0  106M  0 part /boot/efi
    sdb       8:16   0 27.9G  0 disk
    ```

<Message type="note">
  The Scaleway ecosystem uses [GB](https://en.wikipedia.org/wiki/Gigabyte) to define storage sizes and not [GiB](https://en.wikipedia.org/wiki/Gibibyte) as the default on linux.
</Message>

### Formatting the Block volume

Formatting your volume prepares it for storing files.

<Message type="important">
 The procedure below describes how to format your volume using the `mkfs` command, which will **erase all data on the volume**.
</Message>

1. Create a file system with the following command. This command uses the `ext4` file system, though you can choose another if you prefer.
    ```
    # Make sure that you replace `/dev/sdX` with the name of your volume
    mkfs.ext4 /dev/sdX
    ```
2. Run the following command to check that your file system was correctly created.
    ```
    lsblk -f
    ```

  You should see an output like the following. Check that the `FSTYPE` field matches `ext4` for your Block volume. In this example, we have formatted the `sdb` volume.

  ```sh no-copy
    root@scw-festive-agnesi:~# lsblk -f
    NAME FSTYPE FSVER LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
    sda
    ├─sda1
    │    ext4   1.0   cloudimg-rootfs
    │                       cf5b092b-9a8b-49e9-980c-b44b5e3ed197   14.5G    18% /
    ├─sda14
    │
    └─sda15
        vfat   FAT32 UEFI  D590-3FD4                              98.3M     6% /boot/efi
    sdb  ext4   1.0         d36bdf8b-b2ff-4e2b-9736-cc05940aea35
  ```

---

### Creating the mount point and mounting the Block volume

Once you have created your file system, you need to define where you want to mount your volume, and create a mount point (directory) for it.

1. Create the mount point. You can replace `block-volume` with another name for your mount point.
    ```
    mkdir /mnt/block-volume
    ```
2. Mount the volume. We recommend that you use the `defaults` option, as in the command below.
    ```
    # Replace sdX with the name of your volume
    mount -o defaults /dev/sdX /mnt/block-volume
    ```

    If you want to see all available options, you can run `man mount` on your Instance.

3. Run the following command to check if your volume was properly mounted:
    ```
    lsblk
    ```

    You should see an output like the following. Check the `MOUNTPOINT` field.

    ```
    root@scw-festive-agnesi:~# lsblk
    NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
    sda       8:0    0 18.6G  0 disk
    ├─sda1    8:1    0 18.5G  0 part /
    ├─sda14   8:14   0    4M  0 part
    └─sda15   8:15   0  106M  0 part /boot/efi
    sdb       8:16   0 27.9G  0 disk /mnt/block-volume
    ```

The `sdb` volume is mounted at `/mnt/block-volume`.

### Using fstab for persistent mounting

With the current configuration, your volume will not be mounted automatically upon reboot. Use the `/etc/fstab` file to ensure the reboot does not impact your file system.

Run the following command to make sure your volume is automatically mounted to your Instance upon reboot. You must replace `sdX` with your volume.

```bash
echo "UUID=$(blkid --output value /dev/sdX | head -n1) /mnt/block-volume ext4 defaults 0 0" >> /etc/fstab
```