Short answer: Build scripts + standard layout. (I'm a Debian guy) I used 'dpkg -l' to check what all I had currently installed and narrowed down what packages

Short answer: Build scripts + standard layout. (I'm a Debian guy) I used 'dpkg -l' to check what all I had currently installed and narrowed down what packages I was still using. Check /etc/init.d for start up scripts. Hard files on disk are easy to migrate, live migrating MySQL data is more tricky, but my personal sites don't really have that much going on. I always keep a .tar.gz of the entire server for future reference. Move over as much as possible and try to get things running. Save your .bash_history and get a build script going. Pull any /etc/ config files you are missing. Reinstall your required packages. Test your new site via editing /etc/hosts, then move the DNS. Watch your logs and look for 404 erors for files you didn't copy over correctly. It takes time, but if you use an organized and repeatable process, it can take less time in the future.