I've been planning my move of a 25gb MySQL db over to RDS.

I decided to have a downtime window in the middle of the night, versus doing a live move. I am moving from a dedicated datacenter to AWS all at once, so I'm in a different situation than those moving from an EC2 mysql instance to RDS, which should be a lot easier.

I followed the instructions from the RDS instructions, which tell you to break up mysqldump files great than 1GB and use mysqlimport to send them over.

I did some benchmarking and found the import time wasn't linear on file size. This may have to do with the fact that I was using the 1.7GB instance (which i'm upgrading to 15gb for the live site).