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Croad Langshan
Asked: 2016-02-05 16:31:07 +0800 CST

By what mechanism is update-manager supposed to be automatically started?

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I'm trying to support a naive user remotely (using teamviewer). She has a problem where update-manager is not automatically starting (had not shown an software updates window for weeks until today). Checking the "Software & Updates" settings, everything looks fine (check for updates daily, display immediately when there are security updates).

So, how is update-manager supposed to be automatically started? (if I know this I can try to debug) For example, to illustrate the kind of answer I'm hoping for:

  • aptd? Via what configuration, triggered how?
  • Some init.d script? Which one?
  • upstart? Which job file?
  • systemd? Which unit file?
  • cron? Which crontab?

Bonus points for clues re why it might be failing!

15.10

1 Answers

  1. Best Answer

    The mechanism is:

    • /etc/cron.daily/apt runs apt-get update daily. The actual update is done at a randomized time to avoid the "thundering herd" problem
    • Long running process update-notifier uses GIO (presumably itself using inotify) to watch certain files touched by apt for changes when there are updated packages to install (it also monitors for other things, like new ubuntu releases)
    • When there are updates, update-notifier runs update-manager to inform the user (if that is what it is configured to do)

    In my case I'm running Gnome Shell, and it appears that gnome-session runs update-notifier. Presumably Unity arranges to run it by other means.

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