In Ubuntu 18.04.6, you can disable the “Upgrade Available” popup/message in a few ways.
Method 1 — Disable Release Upgrade Notifications (Recommended)
Open Terminal and run:
sudo nano /etc/update-manager/release-upgrades
Find this line:
Prompt=lts
Change it to:
Prompt=never
Save and exit:
Press
CTRL + O→ EnterPress
CTRL + X
Then restart update-manager:
sudo systemctl restart unattended-upgrades
or simply reboot.
Method 2 — Disable Update Notifier Popups
Run:
gsettings set com.ubuntu.update-notifier no-show-notifications true
This hides desktop notification popups.
To enable again later:
gsettings set com.ubuntu.update-notifier no-show-notifications false
Method 3 — Disable GUI Update Checks Completely
Go to:
Software & Updates → Updates
Change:
“Automatically check for updates” →
Never“Notify me of a new Ubuntu version” →
Never
Method 4 — Remove Update Notifier Package (Permanent)
If you never want upgrade popup messages:
sudo apt remove update-notifier update-manager
But this also removes graphical update management tools.
Verify Current Setting
Check:
cat /etc/update-manager/release-upgrades
You should see:
Prompt=never
This will stop messages like:
New release '20.04 LTS' available
Run 'do-release-upgrade'
