Control Mounting and Unmounting of Filesystems Part 1 Mount at boot

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:

ls /mnt/

1.2 Mount an XFS Filesystem

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

sudo mount /dev/vdb1 /mnt

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

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:

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:

sudo umount /mnt

Then verify it’s no longer mounted:

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

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:

sudo vim /etc/fstab

Append:

/dev/vdb1    /mybackups    xfs    defaults    0    2

Note

If you don’t plan to reboot immediately, apply the new mounts with:

sudo mount -a

2.4 Verify and Reboot

Confirm /mybackups is not yet mounted:

ls /mybackups/
lsblk | grep mybackups

Reboot the system:

sudo systemctl reboot

After login, verify the mount:

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:

/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:

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

sudo blkid /dev/vdb1
# /dev/vdb1: LABEL="FirstFS" UUID="9ab8cfa5-2813-4b70-ada0-7abd0ad9d289" TYPE="xfs"

4.2 Example `/etc/fstab` Entry with UUID

UUID=9ab8cfa5-2813-4b70-ada0-7abd0ad9d289    /mybackups    xfs    defaults    0    2

Links and References

Watch Video

Watch video content