Mount External Storage as Read-Only in Ubuntu
You can mount external storage as read-only in Ubuntu to protect your data from accidental modification or deletion.
Making an external drive read-only prevents any user from adding, deleting, or changing files on it, offering a layer of protection for critical data.
This functionality is particularly useful for shared computers or when you want to ensure the integrity of a drive’s contents, such as a drive containing important backups or installation media for Ubuntu 22.04 LTS.
By default, Ubuntu mounts external drives in read-write mode, allowing full access. This tutorial shows you how to change that behavior for specific drives or for all external storage.
Open the Terminal and run `gsettings set org.gnome.desktop.lockdown mount-removable-storage-devices-as-read-only true`. To allow writing again, use `gsettings set org.gnome.desktop.lockdown mount-removable-storage-devices-as-read-only false`.
Enable or disable mounting external storage devices as read-only
Ubuntu lets you choose if external storage devices are automatically mounted as read-only, meaning you can view files but not change them. This setting uses a system called org.gnome.desktop.lockdown, which is standard on newer Ubuntu versions and works on both X11 and Wayland.
To make this change, you’ll use the Terminal. You can open it by pressing the Super key and searching for ‘Terminal,’ or by using the shortcut Ctrl+Alt+T.

To make all external drives read-only, type this command and press Enter:
gsettings set org.gnome.desktop.lockdown mount-removable-storage-devices-as-read-only true
To revert this and allow writing to drives again, use this command:
gsettings set org.gnome.desktop.lockdown mount-removable-storage-devices-as-read-only false
Enable or Disable mounting storage devices as read-only devices using the Dconf Editor
You can also change how external storage devices mount using a visual tool called Dconf Editor, which is similar to Windows’ Registry Editor. This tool lets you adjust system settings that aren’t always easy to find. To use it, first install Dconf Editor by running a simple command in your terminal.
First, install the tool by running this command in your terminal:
sudo apt update && sudo apt install dconf-editor
Read more about installing software on Ubuntu here: How to add or remove software on Ubuntu Linux

After installing, open Dconf Editor from your app menu. Navigate through these folders:
org -> gnome -> desktop -> lockdown
Find the setting labeled “mount-removable-storage-devices-as-read-only” and toggle the switch to “On.”

When this is on, any USB drive you plug in will be read-only. You’ll see a notification or a lock icon indicating the device can’t be written to.

Conclusion
You’ve learned how to control whether external drives on your Ubuntu computer mount as read-only, preventing accidental changes. While this method is good for desktop use, system administrators might prefer using udev rules for a more permanent, system-wide way to manage how drives are mounted.
If you have questions or need help, please use the comment section below.
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Richard
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Richard, a writer for Geek Rewind, is a tech enthusiast who loves breaking down complex IT topics into simple, easy-to-understand ideas. With years of hands-on experience in system administration and enterprise IT operations, he’s developed a knack for offering practical tips and solutions. Richard aims to make technology more accessible and actionable. He's deeply committed to the Geek Rewind community, always ready to answer questions and engage in discussions.
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