I would like to know how to rip a dvd with a cdrom drive, or if this is possible. Any drawbacks?

You don't. Not possible. Well I guess the fact that it is not possible could be considered a draw back.

Get yourself a DVDRom, they don't cost much. If you want a more complete answer you could try searching for previous posts where people have asked the same question... But basically DVD's require a different laser to the one found in CDRom's.

Majority of dvdrom drive will however read cd's so you can chuck that cdrom drive out