Per Make apt-get (or aptitude) run with -y but not prompt for replacement of configuration files? I did the following: ec2run ami-3c994355 --region us-east-1 -n 1 -t m1.large -z us-east-1d On the machine: sudo apt-get update sudo apt-get -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" dist-upgrade I still get a prompt asking me which config file I want to use. These are the lines that come before the prompt: Setting up grub-pc (1.99-21ubuntu3.1) ... then: +-------------------------------------------------------¦ Configuring grub-pc +-------------------------------------------------------+ ¦ A new version of configuration file /etc/default/grub is available, but the version installed currently has been locally modified. ¦ ¦ ¦ ¦ What do you want to do about modified configuration file grub? ¦ ¦ ¦ ¦ install the package maintainer's version ¦ (Unrelated, was this too much information?)