All Debian based systems use APT as package management tool. The list of repositories is defined in /etc/apt/sources.list and .list files found inside /etc/apt/sources.d/. Updates can be installed directly using apt-get, or via the GUI.

Apt sources.list files list one package repository per line, with the most preferred source listed first. Empty lines are ignored, and a # character anywhere on a line marks the remainder of that line as a comment. The information available from the configured sources is acquired by apt-get update.

File /etc/apt/sources.list
deb http://ftp.debian.org/debian jessie main contrib

# security updates
deb http://security.debian.org jessie/updates main contrib

In addition, Proxmox VE provides three different package repositories.

Proxmox VE Enterprise Repository

This is the default, stable and recommended repository, available for all Proxmox VE subscription users. It contains the most stable packages, and is suitable for production use. You need a valid subscription key to access this repository. The pve-enterprise repository is enabled by default:

File /etc/apt/sources.list.d/pve-enterprise.list
deb https://enterprise.proxmox.com/debian jessie pve-enterprise
Note You can disable this repository by commenting out the above line using a # (at the start of the line). This prevents error messages if you do not have a subscription key. Please configure the pve-no-subscription repository in that case.

As soon as updates are available, the root@pam user is notified via email about the available new packages. On the GUI, the change-log of each package can be viewed (if available), showing all details of the update. So you will never miss important security fixes.

Proxmox VE No-Subscription Repository

As the name suggests, you do not need a subscription key to access this repository. It can be used for testing and non-production use. Its not recommended to run on production servers, as these packages are not always heavily tested and validated.

We recommend to configure this repository in /etc/apt/sources.list.

File /etc/apt/sources.list
deb http://ftp.debian.org/debian jessie main contrib

# PVE pve-no-subscription repository provided by proxmox.com,
# NOT recommended for production use
deb http://download.proxmox.com/debian jessie pve-no-subscription

# security updates
deb http://security.debian.org jessie/updates main contrib

Proxmox VE Test Repository

Finally, there is a repository called pvetest. This one contains the latest packages and is heavily used by developers to test new features. As usual, you can configure this using /etc/apt/sources.list by adding the following line:

sources.list entry for pvetest
deb http://download.proxmox.com/debian jessie pvetest
Warning the pvetest repository should (as the name implies) only be used for testing new features or bug fixes.