I've only used it on Centos, soI thought I'd make a quick Debian guide:
Install the DRBD Package
apt-get install drbd8-utils
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libswfdec-0.8-0
Use 'apt-get autoremove' to remove them.
The following........
Refusing to automatically import keys when running unattended.
Use "-y" to override.
When using echo y|yum install gcc
Fix with rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY*........