Good news for Linux users that like Google Drive, at the present there is not official Google application that allows Google Drive users to backup and synchronise between computer running on Linux and the Google cloud, but there is one application in beta development called Insync http://www.insynchq.com that allows you to do that and some more. It supports multiple accounts, I can synchronise my company’s account together with my personal Google Drive accounts and every e-mail address has its own file directory in the structure, so users may be well organized.
Unlike Google Drive official application for Windows, Insync actually keeps real hard copy of the files synchronized on users computer, not just symbolic links.
After installation, a small icon appears in your taskbar, you may add Google accounts to synchronize and it will not only do that, but it also informs about how much space is left on each of the connected accounts.
Insync automatically converts files created in Google Drive to OpenDocument format in my Ubuntu install, so I can have copy of my Google Drive in my /home/Insync/username@gmail.com folder, after I open, edit and save the file, it appears on Google Drive updated as expected.
I am missing a way to be able to add custom folders to synchronize with selected Google Account, so Insync would also behave as a ultimate backup tool, but I keep my fingers crossed for the Insync developers to keep this application improved and free somehow.