How to backup a MySQL database without slowing the application?
A) Take the backup from a replicating slave. Zero performance loss.

B) Use LVM to take a consistent snapshot. Copy the database files at your leisure.

C) Use Rsync over a remote connection to copy the data files, then do a final Rsync with the database briefly locked for a couple seconds.

As an aside, how are they taking a consistent backup with MyISAM tables without LOCKING the application for 8 hours straight? It doesn't seem possible.