Defraggler seems to have a very ineffective strategy for defragging large files with lots of fragments. Even when there is lots of free space, it grinds away shuffling files around, while slowly slowly reducing the number of fragments of the current target. Or at least that's the way it looks from the entertainment.
I'm sure you get lots of suggestions, second guessing the strategy used. Here's mine. Before you start a defrag
step, calculate a metric for the work you're about to do which weights both the number of megabytes to be moved
and the number of files to be moved. Compare that to the cost of moving the entire file to an open space.
Case in point; my primary backup drive has a mix of hundreds of thousands of small files (blame windows and adobe for that) and a few gargantuan files (blame virtualbox for that). It has 25% free space in a 2TB partition. It has taken a week of
defragging to reduce the %fragmented report from 25% to 6%
