How to transfer my wallet.dat to dedicated Ubuntu server
Though not really bitcoin related...
How are the two systems connected? I mean, can you already login via ssh? Or do you only have a terminal running on both, and no ssh daemon? 

If no ssh daemon, then netcat is the tool of choice. 
If ssh daemon is running, use secure copy tool:

scp -port source target


e.g.: 

scp -P 22022 ~/.bitcoin/wallet.dat 192.168.92.117:/home/mybitcoinuser/.bitcoin


And lastly, if the target server doesn‘t run ssh daemon, you can for sure start one in your terminal, and execute the scp from the target server (adopting the source and target).

There is a capital P when using scp.