---
title: Volumes on Linux
sidebar_position: 3
---

# Make Your Volume Available for Use on Linux

After you attach a block storage volume to your node, it is exposed as a **block device**. You must format the volume with a filesystem and mount it before use. Once mounted, you can access the volume like any other directory, and all data written to it is stored on the attached block storage volume.

Suppose your node has a root device as **/dev/vda1**, and you have attached a new empty volume using **/dev/vdb**.  
The following steps explain how to make this volume available for use.

---

### 1. Connect to Your Instance
Log in to your instance using SSH.

```bash
ssh <username>@<public-ip>
````

---

### 2. List Available Disks

List all attached block devices to identify your new volume:

```bash
lsblk
```

This displays all available disks and their mount points (if any).
You can identify your attached volume (for example, `/dev/vdb`) by checking which device is unmounted.

---

### 3. Check if the Volume Has a Filesystem

Use the following command to verify if the attached volume is empty or already formatted:

```bash
sudo file -s /dev/vdb
```

* If the output shows `data`, the volume has **no filesystem** and needs formatting.
* If it shows a type like `XFS` or `ext4`, it already has a filesystem (for example, if created from a snapshot).

---

### 4. Create filesystem (if Empty)

If the volume is empty, create a filesystem using `mkfs`.
This example uses **XFS**, but you can also use `ext4` depending on your needs.

```bash
sudo mkfs -t xfs /dev/vdb
```

:::danger
This command **erases all existing data** on the volume.
Do not run this if the volume was created from a snapshot or already contains data.
:::

If you get an error like `mkfs.xfs: command not found`, install the XFS utilities:

```bash
sudo yum install -y xfsprogs
# or on Ubuntu
sudo apt install -y xfsprogs
```

---

### 5. Create a Mount Point

Create a directory where you will mount the volume (for example, `/data`):

```bash
sudo mkdir /data
```

---

### 6. Mount the Volume

Mount the formatted volume to the directory you created:

```bash
sudo mount /dev/vdb /data
```

You can now verify that the filesystem is mounted successfully:

```bash
df -h
```

---

### 7. Unmount the Volume (Optional)

To safely unmount the volume:

```bash
sudo umount /data
```

---

### 8. Make the Mount Persistent After Reboot

Mount points are **not automatically preserved** after a reboot.
To ensure your volume mounts automatically at startup, you must add it to the `/etc/fstab` file using its **UUID**.

#### Step 1: Find the UUID

Run the following command to get the UUID of the volume:

```bash
sudo blkid /dev/vdb
```

Example output:

```
/dev/vdb: UUID="e7c5b2f2-8b2a-4e13-b9a9-bb3f122a91f1" TYPE="xfs"
```

#### Step 2: Edit `/etc/fstab`

Open the file in an editor:

```bash
sudo nano /etc/fstab
```

Add the following line at the end (replace the UUID with your own):

```
UUID=e7c5b2f2-8b2a-4e13-b9a9-bb3f122a91f1   /data   xfs   defaults,nofail   0   2
```

#### Step 3: Verify Configuration

Apply the configuration and check for errors:

```bash
sudo mount -a
```

If no errors appear, your setup is correct.
Reboot the node to confirm persistence:

```bash
sudo reboot
```

After reboot, verify that the mount is active:

```bash
df -h
```

You should see `/data` listed as mounted.

---

:::note

* Volumes created from snapshots typically already include a filesystem — skip formatting in such cases.
* Always verify the device name using `lsblk` before running `mkfs` to avoid data loss.
* You can use `ext4` instead of `xfs` if preferred — adjust commands accordingly.
* For DR resources, use persistent mounts via UUID to ensure consistent behavior across reboots or recoveries.
:::


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