How to perform unattended upgrades

I have been using unattended upgrades on development machines since the end of last November, when I installed Debian Jessie release.


You are required to install the following package.

$ sudo apt-get install unattended-upgrades


Location of the configuration file

Configuration is stored inside /etc/apt/apt.conf.d/50unattended-upgrades file.

Supported package sources

Use Origins-Pattern directive to define examined package sources.

Only packages from matched repositories will be upgraded.

Use following code to upgrade packages only from the current distribution including additional updates.

Unattended-Upgrade::Origins-Pattern {
${distro_codename} macro will be expanded to distribution name - it will be jessie in this case.

As an alternative to the previous example, use following code to install every upgrade available through the used sources lists.

Unattended-Upgrade::Origins-Pattern {

The following example will help you understand keywords used in the above-mentioned configuration samples.

$ apt-cache policy
 100 jessie-backports/main amd64 Packages
     release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=main
Keyword Definition Example
o origin Debian Backports
a archive jessie-backports
n codename jessie-backports
l label Debian Backports
c component main
site FQDN


Use blacklist directive to define list of not upgraded packages.

Unattended-Upgrade::Package-Blacklist {

Remove orphaned dependencies

Use the following directive to automatically remove packages that were installed to satisfy dependencies, but currently are not needed.

This directive is equivalent to apt-get autoremove command.
Unattended-Upgrade::Remove-Unused-Dependencies "true";

Bandwidth cap

The following code will impose bandwidth cap [KB/s] on apt utilities.

Acquire::http::Dl-Limit "400";

E-mail notifications

Use following code to define email address and set notification for every action.

Unattended-Upgrade::Mail "root";
Unattended-Upgrade::MailOnlyOnError "false";

Other options

More options are available for user like whitelist or automatic reboot. These are well documented inside configuration file, so I will just skip them for the sake of simplicity.


Update and upgrade process is initiated daily from /etc/cron.daily/apt cron task.

Installation process will not automatically enable unattended upgrades.

The interactive way to enable or disable unattended upgrades is to reconfigure package.

$ sudo dpkg-reconfigure unattended-upgrades

The non interactive way to enable whole process requires simple copy command.

$ sudo cp /usr/share/unattended-upgrades/20auto-upgrades /etc/apt/apt.conf.d/20auto-upgrades

The non interactive way to disable whole process is very similar to the above one.

$ sudo cp /usr/share/unattended-upgrades/20auto-upgrades-disabled /etc/apt/apt.conf.d/20auto-upgrades

The /usr/share/unattended-upgrades/20auto-upgrades file contains only two directives that enable automatic update and upgrade process. The second one contains opposite settings.

APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";

Ending notes

Please read unattended-upgrade manual page and /usr/share/doc/unattended-upgrades// documentation.

This software is often used together with apt-listchanges and apticron apt notification utilities. I will not describe these useful packages now, but remember that you can always transmit a mail to an external SMTP server using msmtp utility.

Milosz Galazka's Picture

About Milosz Galazka

Milosz is a system administrator working for a successful Polish company and a long time supporter of Free Software Foundation and Debian operating system.

Gdansk, Poland