I installed Debian jessie on a laptop with relatively new hardware, e.g. a Skylake i7-6600U processor, so I had to install the kernel and firmware-iwlwifi driver from jessie-backports. /etc/apt/sources.list has this line

deb http://ftp.us.debian.org/debian/ jessie-backports main non-free contrib

I then installed linux-image-4.5.0-0.bpo.2-amd64 and firmware-iwlwifi=20160110-1~bpo8+1. Now that these are correctly installed, does it make sense to remove that line from /etc/apt/sources.list?

I'd like these packages to receive updates from the backports repo if any are available, but I don't want any other packages to get updates from jessie-backports. I have APT::Default-Release "jessie"; in /etc/apt/apt.conf.d/70debconf, so that should be enough to guarantee this, right?

  • I am looking into this more, but I think that the default release should be APT::Default-Release "stable";
    – Peschke
    Jun 1, 2016 at 17:25
  • @ElixirofLove Isn't that related to this answer in that it may have consequences in the future when jessie becomes oldstable instead of stable?
    – Michael A
    Jun 1, 2016 at 17:30
  • Real machine, not vmware, right? Jun 1, 2016 at 20:14
  • @RuiFRibeiro Yes, a laptop (Lenovo X1 Carbon gen 4).
    – Michael A
    Jun 2, 2016 at 1:05

2 Answers 2


As https://backports.debian.org/Instructions/ says:

All backports are deactivated by default (i.e. the packages are pinned to 100 by using ButAutomaticUpgrades: yes in the Release files.

So backports are set to 100 server side - i.e. in the Release file on the server. You do not need to do anything special to make this work. One of the consequences is that you will be upgraded to new versions of the backports that are already installed, if/when they become available. However, no new backports will be installed unless you explicitly install them with

apt-get install -t jessie-backports pkgname

So you want to leave the backports line in there.

  • Running sudo aptitude safe-upgrade still shows me updates to the kernel version that comes from the stable repos (3.16) as opposed to the version that came from backports (4.5). Since I left the backports line in sources.list, is it still safe to upgrade the 3.16 package? I'm thinking I should reinstall the 4.5 version after doing this to make sure update-initramfs picks up the 4.5 version because I can't boot with the 3.16 kernel.
    – Michael A
    Jun 29, 2016 at 1:57
  • Yes, both versions will be upgraded if they are both still installed. And sure, it's fine to upgrade both packages. You don't have to use 3.16 if you don't want to. There's no problem with having multiple kernels installed alongside each other, as long as they are not too old. Jun 29, 2016 at 8:39
  • Thank you. I just wasn't sure if the most recent version would be used by default.
    – Michael A
    Jun 29, 2016 at 12:43

Yes, leave the backports repository line in place, otherwise you won't get updates (including, for example, security fixes).

The backports repository actually makes use of an apt feature in the Release file that makes apt already not want to install anything from backports (it sets the priority lower). You do not need to set APT::Default-Release (at least not for backports).

BTW: If you want to add additional settings to apt, it's probably best to either edit /etc/apt.conf or create your own file such as /etc/apt/apt.conf.d/70local-default-release, otherwise you'll get annoying configuration file prompts on upgrade. And also confuse anyone trying to understand your setup ("how did that line get in there??")

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