The sources.list
for Debian Testing is not compatible with Debian 9 (codename Stretch)
Here is an example sources.list
:
deb http://ftp.us.debian.org/debian/ stretch main contrib non-free
deb http://ftp.us.debian.org/debian/ stretch-updates main contrib non-free
deb http://security.debian.org/debian-security/ stretch/updates main contrib non-free
The following sources.list
attempts to serve content close to your location using redirection:
deb http://deb.debian.org/debian/ stretch main contrib non-free
deb http://deb.debian.org/debian/ stretch-updates main contrib non-free
deb http://deb.debian.org/debian-security/ stretch/updates main contrib non-free
To update your system, proceed as usual:
apt-get update # Update package information from sources
apt-get upgrade # Upgrade packages
apt-get dist-upgrade # Upgrade packages that depends on new dependencies
I do recommend doing security updates either manually or doing it as part of planned upgrades via other provisioning systems, after testing in a pre-production environment. In alternative, you might also install the package unattended-upgrades
.
You can read more information here