automatic security upgrade

Its purpose is to keep the computer current with the latest security (and other) updates automatically. If you plan to use it, you should have some means to monitor your systems, such as installing the apt-listchanges package and configuring it to send you emails about updates. And there is always /var/log/dpkg.log, or the files in /var/log/unattended-upgrades

To install these packages, run the following command as root:

apt-get install unattended-upgrades apt-listchanges

To activate unattended-upgrades, you need to ensure that the apt configuration stub /etc/apt/apt.conf.d/50auto-upgrades contains at least the following lines: 

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

This file can be created manually or by running the following command as root:

dpkg-reconfigure -plow unattended-upgrades

source: https://wiki.debian.org/UnattendedUpgrades

messed up locales

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LC_CTYPE = “UTF-8”,
LANG = “en_US.UTF-8”
are supported and installed on your system.

Solution:

sudo dpkg-reconfigure locales

Choose: en_US.UTF-8
Then put:

LC_ALL=en_US.UTF-8

in /etc/environment

Log off and log on again