How to Perform OS, Security and Package Updates on Debian

Debian uses deb packages from repositories to manage the installation, upgrading and removal of software on your Debian system, including OS and Security updates. In order to update your system manually you will have to connect to your Debian host via SSH to have access to the terminal.

Applying Debian security updates only

Connect to your Debian system via SSH. Once you are in the terminal, enter the following commands:
1. grep security /etc/apt/sources.list | tee /etc/apt/security.sources.list
2. apt-get update
3. apt-get upgrade -o Dir::Etc::SourceList=/etc/apt/security.sources.list

Press “Y” and “Enter”. Security updates will be installed and your system will be up to date.
To check and apply updates at a later stage do this:
1. apt-get update
2. apt-get upgrade -o Dir::Etc::SourceList=/etc/apt/security.sources.list

Updating all packages (OS and other installed packages)

Run this command:
apt-get update && apt-get upgrade
Press “Y” and “Enter”. OS and applications will be up to date.

Updating a single package

To update a single package on the system, use the apt-get command + the package name we want to update.
To update 3CX SBC run this command:
apt-get update && apt-get upgrade 3cxsbc
To find out the name of the package you have installed on your system:
dpkg -l | more
Press “space” to scroll through the list of installed packages. See their version and of course obtain the exact package name in order to update it with the:
apt-get update && apt-get upgrade packagename command.