Best way to install/scale OpenVAS?

One fact at the beginning, everything that interfere with your raw network packets ruins your installation.

You wanna have raw direct network access as root for the OpenVAS (Scanner) for the rest of GVM it depends on your needs, setup and environment. Almost all pre-compiled packets are outdated, broken or missing some features. Some come with really insecure default setups introduced by the maintainers. I suggest you read a bit here in the forum, many users maintain and run a GSE with lot of success, additional please check our FAQ here: