Cannot disable automatic update checks on Kubuntu 18.04

Solution 1:

To disable automatic upgrades in Kubuntu 18.04, run:

$ sudo dpkg-reconfigure --priority=low unattended-upgrades

and when prompted Automatically download and install stable updates?, choose "No" and follow the remaining prompts. To see the status of automatic upgrades, run:

$ apt-config dump APT::Periodic::Unattended-Upgrade

The value produced (an integer) means how often to update automatically, in days. A zero value means disabled.

Solution 2:

At my 18.04.1 installation there was no file /etc/apt/apt.conf.d/10periodic.

After a short search I found:

/etc/apt/apt.conf.d/20auto-upgrades

There I could disable my auto-updates. Maybe you could also have a look there for your solution.

I just zero-ed the values; so my content of /etc/apt/apt.conf.d/20auto-upgrades is now:

APT::Periodic::Update-Package-Lists "0";
APT::Periodic::Unattended-Upgrade "0";
APT::Periodic::Download-Upgradeable-Packages "0";