If you have installed the full desktop version of Ubuntu, everything you need is already installed and running. Package updates can be scheduled from the desktop. For the server or costumised installation then you need to install apt-cron.
If you want to change when the system update itself in a full ubuntu desktop version,you have to go to System–>Administration –>Software sources
Then shedule automatic update for daily. weekly …
Now if you have an costumised ubuntu or an ubuntu server for example, and you want that the updates to be installed automaticaly, then you may need to install apt cron.
cron-apt package, combines the cron and apt utilities, and provides flexibility and a simpler interface as well as supporting e-mail alerts on errors or new information.
cron-apt automatically adds the
-d flag, so you’ll have to run
apt-get dist-upgrade to install the changes. You can install
cron-apt using apt:
sudo apt-get install cron-apt
You can find the configuration file of cron-apt in /etc/cron-apt/config, except how often the script runs, that’s depended on
cron so you can find it in /etc/cron.d/cron-apt. One popular configuration change is to add the line:
This will make sure an e-mail is always sent when the update runs, rather than only when an error occurs.
Add cron-apt to cron.daily
To make cron-apt be executed by Anacron, create a link in /etc/cron.daily or /etc/cron.weekly. For example:
sudo ln -s /usr/sbin/cron-apt /etc/cron.weekly/
For daily updates :
sudo ln -s /usr/sbin/cron-apt /etc/cron.daily/
For Hourly updates :
sudo ln -s /usr/sbin/cron-apt /etc/cron.hourly