> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Control Mounting and Unmounting of Filesystems Part 1 Mount at boot

> Learn to manually mount filesystems, configure automatic mounts at boot, enable swap partitions, and use UUIDs for device identification in Linux.

Linux attaches storage devices to the directory tree by “mounting” them on existing folders. In this guide, you’ll learn how to:

* Manually mount and unmount filesystems
* Configure automatic mounts at boot using `/etc/fstab`
* Enable swap partitions at startup
* Use UUIDs for stable device identification

***

## 1. Manual Mounting and Unmounting

### 1.1 Verify an Empty Mount Point

A common temporary mount directory is `/mnt`. Confirm it’s empty:

```bash theme={null}
ls /mnt/
```

### 1.2 Mount an XFS Filesystem

Assuming you created an XFS filesystem on `/dev/vdb1`, mount it to `/mnt`:

```bash theme={null}
sudo mount /dev/vdb1 /mnt
```

Now `/mnt` is the root of that filesystem. Create a test file and verify:

```bash theme={null}
sudo touch /mnt/testfile
ls -l /mnt/
# -rw-rw-r--. 1 aaron aaron 0 Jan 31 14:30 testfile
```

Use `lsblk` to confirm the mount point:

```bash theme={null}
lsblk
# NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
# vdb     8:16   0   10G  0 disk 
# └─vdb1  8:17   0    4G  0 part /mnt
```

### 1.3 Unmount the Filesystem

To detach the filesystem:

```bash theme={null}
sudo umount /mnt
```

Then verify it’s no longer mounted:

```bash theme={null}
lsblk
ls /mnt/
```

***

## 2. Automatic Mounting at Boot with `/etc/fstab`

The `/etc/fstab` file defines filesystems to mount automatically during system startup.

### 2.1 Create the Mount Point

```bash theme={null}
sudo mkdir /mybackups
```

### 2.2 Understand `/etc/fstab` Fields

| Field             | Description                                      | Example                   |
| ----------------- | ------------------------------------------------ | ------------------------- |
| Device            | Block device path or UUID                        | `/dev/vdb1` or `UUID=...` |
| Mount point       | Directory to attach the filesystem               | `/mybackups`              |
| Filesystem type   | `xfs`, `ext4`, `swap`, etc.                      | `xfs`, `swap`             |
| Options           | Mount options, e.g., `defaults`, `rw`, `noexec`  | `defaults`                |
| Dump              | `0` = disable, `1` = enable (for `dump` utility) | `0`                       |
| Pass (fsck order) | `0` = skip, `1` = root, `2` = other filesystems  | `2`                       |

### 2.3 Add an XFS Entry

Open `/etc/fstab` in your editor:

```bash theme={null}
sudo vim /etc/fstab
```

Append:

```fstab theme={null}
/dev/vdb1    /mybackups    xfs    defaults    0    2
```

<Callout icon="lightbulb" color="#1CB2FE">
  If you don’t plan to reboot immediately, apply the new mounts with:

  ```bash theme={null}
  sudo mount -a
  ```
</Callout>

### 2.4 Verify and Reboot

Confirm `/mybackups` is not yet mounted:

```bash theme={null}
ls /mybackups/
lsblk | grep mybackups
```

Reboot the system:

```bash theme={null}
sudo systemctl reboot
```

After login, verify the mount:

```bash theme={null}
ls -l /mybackups/
lsblk | grep mybackups
# vdb1   8:17   0   4G  0 part /mybackups
```

***

## 3. Enabling Swap at Boot

If you created a swap partition on `/dev/vdb3`, add it to `/etc/fstab` so it’s activated at startup.

### 3.1 Add Swap Entry

Edit `/etc/fstab` and append:

```fstab theme={null}
/dev/vdb3    none    swap    defaults    0    0
```

Here, the mount point is `none`, and `0 0` disables dump and fsck.

### 3.2 Verify Swap

Reload systemd (or reboot) and check:

```bash theme={null}
sudo systemctl daemon-reload
sudo swapon --show
# NAME        TYPE      SIZE USED PRIO
# /dev/vdb3   partition 2G   0B   -2
```

***

## 4. Using UUIDs Instead of Device Names

Device names can change if hardware is reconfigured. UUIDs remain constant.

### 4.1 Retrieve a Device’s UUID

```bash theme={null}
sudo blkid /dev/vdb1
# /dev/vdb1: LABEL="FirstFS" UUID="9ab8cfa5-2813-4b70-ada0-7abd0ad9d289" TYPE="xfs"
```

### 4.2 Example `/etc/fstab` Entry with UUID

```fstab theme={null}
UUID=9ab8cfa5-2813-4b70-ada0-7abd0ad9d289    /mybackups    xfs    defaults    0    2
```

***

## Links and References

* [mount(8) Manual](https://man7.org/linux/man-pages/man8/mount.8.html)
* [fstab(5) Manual](https://man7.org/linux/man-pages/man5/fstab.5.html)
* [XFS Filesystem Documentation](https://docs.kernel.org/filesystems/xfs/index.html)
* [Linux Swap – ArchWiki](https://wiki.archlinux.org/title/Swap)
* [blkid(8) Manual](https://man7.org/linux/man-pages/man8/blkid.8.html)

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