[otrs] otrs upgrade problem

Hi, I tried to upgrade from 2.04 to 2.4. I followed every steps but the problem after 2.1 version its breaks lot of thing. Is it really possible to very old 2.04 to 2.4. i 've lots of data. aroug 6 Gb posgres.sql. Or is that ovious that some thing will not work from previous version. -ekram