You can export your DP7 IDB and use it to Build a new Cell, but this basically means you install DP7 on the new Server as well and Upgrade it there. Advantage from that is you can still use the old Cell in case the Upgrade fails.
If you want to built up DP9 from scratch you can do that. Importing Barlists works by copying them over from the old Cell. Library/Device Configs can be moved via omnidownload/omniupload. Media and Session-Info can be moved by importing Tapes them via Tapedrive or by using MCF-Files. Be careful with the Licenses since the format has changed.
Suggest to check the Upgrade Whitepaper for DP8.10. Process is virtually identical to DP9