SQL-Databases are empty ... help

I wanted to migrate the G2 to a new server, so I copied the content from the old debian server to a new open linux server - no problem via scp. The problem on da old debian machine was the fact that I couldn´t get the mysql running again. So I checked out the content in /var/lib/mysql and copied to the new server - worked fine, fixed some small issues concerning the chmods and chowns and so on - but hej, the database is nearly empty ... oh my god - ist there any possibility to get an upgrade done with the content from g2data? Please, I need some help over here

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