What is "dist-upgrade" and why does it upgrade more than "upgrade"?

  • I was wondering why upgrade sometimes doesn't want to upgrade certain parts of the system, while dist-upgrade does. Here's an example after running apt-get upgrade:

    apt-get upgrade:

    [email protected]:~$ sudo apt-get upgrade
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    The following packages have been kept back:
      linux-generic linux-headers-generic linux-image-generic
    0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
    

    versus apt-get dist-upgrade:

    [email protected]:~$ sudo apt-get dist-upgrade
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    Calculating upgrade... Done
    The following NEW packages will be installed:
      linux-headers-3.0.0-13 linux-headers-3.0.0-13-generic
      linux-image-3.0.0-13-generic
    The following packages will be upgraded:
      linux-generic linux-headers-generic linux-image-generic
    3 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
    Need to get 48.5 MB of archives.
    After this operation, 215 MB of additional disk space will be used.
    Do you want to continue [Y/n]?
    

    In other words, why can't this be performed by upgrade?

  • jcollado

    jcollado Correct answer

    9 years ago

    From apt-get manual:

    upgrade
       upgrade is used to install the newest versions of all packages
       currently installed on the system from the sources enumerated in
       /etc/apt/sources.list. Packages currently installed with new
       versions available are retrieved and upgraded; under no
       circumstances are currently installed packages removed, or packages
       not already installed retrieved and installed. New versions of
       currently installed packages that cannot be upgraded without
       changing the install status of another package will be left at
       their current version. An update must be performed first so that
       apt-get knows that new versions of packages are available.
    
    dist-upgrade
       dist-upgrade in addition to performing the function of upgrade,
       also intelligently handles changing dependencies with new versions
       of packages; apt-get has a "smart" conflict resolution system, and
       it will attempt to upgrade the most important packages at the
       expense of less important ones if necessary. So, dist-upgrade
       command may remove some packages. The /etc/apt/sources.list file
       contains a list of locations from which to retrieve desired package
       files. See also apt_preferences(5) for a mechanism for overriding
       the general settings for individual packages.
    

    And with the newer apt tool available from 14.04 onwards:

    full-upgrade
       full-upgrade performs the function of upgrade but may also remove
       installed packages if that is required in order to resolve a
       package conflict.
    

    In your particular case, I see, for example, that linux-headers is a virtual package that is provided by both linux-headers-3.0.0-12 and linux-headers-3.0.0-13 and that sounds like the kind of package installation and removal handled by dist-upgrade, but not by upgrade.

    I don't see `full-upgrade` as an option to `apt-get` under 14.04.1.

    I didn't knew about `apt` either but it seems to be a completely diffrent command according to the man page he linked

    @nobar You don't see because it is an option of `apt` and not of `apt-get`... :-) Try `man apt`.

    Okay, I searched and the earliest link I found is for Ubuntu 15.10 (which came out end of 2014 which seams reasonable with Jessie testing) http://manpages.ubuntu.com/manpages/wily/en/man8/apt.8.html

    Small correction. I guess Ubuntu is built from Testing or Unstable branches. In either case it is based on develop versions of Debian and does not necessarily wait for the Stable branch.

    Ubuntu 15.10 actually came out Oct 2015 not 2014.

    @Zboson Yeah, and 14.04 came out not in 2011, but in April 2014... see the pattern?

  • apt-get upgrade is restricted to the case where packages are to be replaced by newer versions, but no package needs to be added or removed. A new version of Firefox, for instance, should be installable with apt-get upgrade.

    However apt-get upgrade will refuse to work when there are additions or removals required by the updated versions. For example, when you have kernel linux-image-3.2.0-10-generic installed and linux-image-3.2.0-11-generic appears, the linux-image-generic package gets updated to depend on the newer version. In order to install the new kernel, you need to run apt-get dist-upgrade.

    Notice how an apt-get upgrade will say that the kernel packages have been held back. That's the cue for using apt-get dist-upgrade.

    Perfect! :D Two more questions... what is used by the graphical update manager in Ubuntu? What is the recommended one?

    The graphical utility, `update-manager`, does not use `apt-get` directly; instead it works with a backend called `aptdaemon`. The standard abilities of `update-manager` are a mix of the `upgrade` and `dist-upgrade` modes of `apt-get`: it can add but not remove packages - it invokes the "Partial upgrade" tool when removals are required. When using the command line, use `apt-get upgrade`. If you see it reports that packages have been "held back", run `apt-get dist-upgrade` to pick up the remaining updates.

  • Basically upgrade will only upgrade existing packages from one version to another. It will not install or remove packages, even if doing so is required to upgrade others. In the case of kernel updates, upgrading the linux-generic package requires installing the new linux-3.0.0-13-generic package, and since upgrade refuses to install or remove packages, it refuses to upgrade linux-generic.

    Sometimes various incompatibilities between packages will require some packages to be removed in order to upgrade others, and that will also require dist-upgrade. Kernel updates will always require dist-upgrade because of how they are handled. Rather than have a kernel package that gets updated, an entirely new kernel package is created each time, and the kernel metapackage is updated to depend on the new kernel package instead of the old. This was done so that you keep the old kernel versions around so that in case there is a problem with booting the new kernel, you can choose the old one from the boot menu and recover.

    Best gist. Still, how to keep a certain package?

  • The apt-get upgrade command will normally only install updates (or fixes) to currently installed packages. Typically a new release of Mozilla Firefox, for instance, would be installed with this command.

    However apt-get upgrade will NOT generally install new releases, where major changes (including removal of packages or GRUB update is required). For example, when a new Linux kernel (linux-image-3.x.x-xx-generic, etc.) is available, the package will not get installed.

    In order to install the new kernel, you will need to run apt-get dist-upgrade. You will be notified when you run apt-get upgrade, as it will say that certain packages have been held back. That's your cue to use: apt-get dist-upgrade.

    This is misleading. `dist-upgrade` will not upgrade to a new release unless `sources.list` has been modified accordingly (and even then, that's not a supported way to upgrade in Ubuntu). When a new kernel is installed with `dist-upgrade`, that's not a *new release of Ubuntu*. It's just a *new package.* Furthermore, the claim "or GRUB update is required" is false. `sudo apt-get upgrade` is perfectly capable of upgrading packages in a situation where GRUB must be updated, so long as no packages are removed and new packages are installed. `update-grub` is run automatically, as always.

    You should write your own answer, as that add no clarity to mine.

    Besides what Eliah mentioned, the essential point is that `apt-get upgrade` will not remove or add packages. If a fix to a package requires a new package, the update will be held back. pablomme's answer, which you revised to be less accurate, is better and I'd advise readers to go to that one.

    Correction: `apt-get upgrade` will never *install* or *remove* any packages. Kernel upgrades are packaged as new packages and as a result, `apt-get upgrade` will never upgrade the kernel. The fact that kernel upgrade does "major" changes such as GRUB configuration is not the reason for the difference between `upgrade` and `dist-upgrade`.

  • Your best option is:

    apt full-upgrade

    -which auto-handles the dependencies when upgrading packages; whereas:

    apt upgrade
    

    -does NOT auto-handle dependencies when upgrading packages.

    -duBtrotterS

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