In this tutorial, I will talk about installing steamos in virtualbox. The reason, I wanted to do this was to play around and see how they have put together a debian distribution. One thing, I noticed from my installation was, despite valve’s suggestion in their FAQ, I would not recommend executing ~/post_logon.sh after installation, because it removed dkms and necessary drivers, that were necessary to boot the OS. I guess, this step was the step to make steamos boot directly into big picture mode. In our case, you will have to select SteamOS from login manager and login into user account named steam to login to the big picture mode. If you want to run above script anyway, at least make a copy of the vdi file, after you have updated the steam client. File size is no more than 4G, if you have selected dynamically expanding disk in virtualbox. Also, as suggested by some posts, there was no need for me to remove nvidia binaries after installation.