How to disable automatic updates on my Linux Ubuntu computers operating radio telescopes, so that the systems are stable.

Yes. On Ubuntu you can disable automatic updates completely, or just stop the update notifications while still updating manually when you choose.

Temporary: stop automatic updates

Open a terminal and run:

sudo systemctl disable --now unattended-upgrades

This stops the automatic background updater service.

You can check its status with:

systemctl status unattended-upgrades

Disable update checks and popups in the GUI

In Ubuntu Desktop:

1. Open Software & Updates
2. Go to the Updates tab
3. Change:
   • “Automatically check for updates” → Never
   • “When there are security updates” → Display immediately or Never
   • “Automatically download and install” → No

Prevent package lists updating automatically

You can also disable the apt timers:

sudo systemctl disable --now apt-daily.timer
sudo systemctl disable --now apt-daily-upgrade.timer

and optionally:

sudo systemctl mask apt-daily.service
sudo systemctl mask apt-daily-upgrade.service

Re-enable later

If you want updates back:

sudo systemctl unmask apt-daily.service
sudo systemctl unmask apt-daily-upgrade.service

sudo systemctl enable --now apt-daily.timer
sudo systemctl enable --now apt-daily-upgrade.timer
sudo systemctl enable --now unattended-upgrades

Recommendation

For an astronomy or SDR system that must stay stable during observations, many people disable automatic updates but still run manual updates periodically:

sudo apt update
sudo apt upgrade

That gives you control over when kernel or driver changes happen.

So, to disable updates on system that must stay stable, what shall I enter?

On your Ubuntu system, enter these commands in a terminal to fully disable automatic updates and update timers while keeping manual updates available:

sudo systemctl disable --now unattended-upgrades

sudo systemctl disable --now apt-daily.timer
sudo systemctl disable --now apt-daily-upgrade.timer

sudo systemctl mask apt-daily.service
sudo systemctl mask apt-daily-upgrade.service

Then reboot once:

sudo reboot

Your system will then stay unchanged until you manually run:

sudo apt update && sudo apt upgrade

That is usually the safest setup for dedicated SDR, radio astronomy, interferometry, or observatory machines where stability matters more than automatic patching.

Is there an app like Windows Update Blocker to do all this for me?

Yes — there are a few GUI tools and lightweight utilities for Ubuntu, although nothing quite as polished as “Windows Update Blocker”.

The closest options are:

• software-properties-gtk (built into Ubuntu)
• Unattended Upgrades configuration tools
• Startup/service managers like Stacer
• Simple custom scripts with desktop launchers

For a stable observatory or SDR machine, the easiest GUI approach is usually:

Built-in Ubuntu GUI

Run:

software-properties-gtk

Then:

Updates tab

• Automatically check for updates → Never
• Automatically download updates → No
• Security updates → Never

That disables most automatic behaviour without touching services manually.

Stacer (nice GUI system manager)

Stacer gives a graphical way to disable startup services including update services.

Official site:

Install with:

sudo apt install stacer

Then:

• Open Stacer
• Go to Services
• Disable:
  • unattended-upgrades
  • apt-daily
  • apt-daily-upgrade

Best long-term solution for observatory systems

For dedicated radio astronomy or interferometry PCs, many people simply:

• disable updates once via terminal
• make a backup image
• only update manually after testing

That is generally more reliable than relying on a GUI toggle utility.