How to mount a Block Storage volume to an Instance

Reviewed on October 10, 2025

A Scaleway account logged into the console
Owner status or IAM permissions allowing you to perform actions in the intended Organization
An Instance
Attached 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

Connect to your Instance with ssh.
```
ssh root@<your_instance_ip>
```

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.

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

Note

The Scaleway ecosystem uses GB to define storage sizes and not GiB as the default on linux.

Formatting the Block volume

Formatting your volume prepares it for storing files.

Important

The procedure below describes how to format your volume using the mkfs command, which will erase all data on the volume.

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
```
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.

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.

Create the mount point. You can replace block-volume with another name for your mount point.
```
mkdir /mnt/block-volume
```
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.

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.

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