Easiest way for fast transfer of files between linux servers?
Solution 1:
rsync
I'd use rsync before I used ftp or tftp.
More options and (in my experience) more reliable transfer.
Solution 2:
tar over ssh is okay, but tar over TCP via netcat is about as low-overhead as you can get! If this is a one-time thing, give this a shot:
On the receiver:
nc -l -p 8989 | tar x
On the sender:
tar cf - /source-path | nc (receiving host ip address) 8989
If this is something you're going to do regularly, I'd probably use rsync.