This is not a bug. Fastfill is designed to be fast ...
You might be right, though I like to believe that I understand how fastfill is supposed to work and posted because:
- the gaps are huge and largely empty (no small file pieces on zooming in, just the larger ones visible here)
- the gap pattern was created into a perfectly empty area that I created before in order to move/defrag the pagefile there (unsucessfully as it ended up on the top but that is not the point here)
- this zone does not contain large files at all (they should nicely fill in)
- there were no other apps running on the computer (no file deletions, creation at the same time)
- an immediate re-run of the same script did fill this zone perfectly (suggesting that it could have been accomplished)
It was an interesting experience to watch MyDefrag filling files in funny patterns into a perfectly empty gap.
Over night I had a chance to put MyDefrag through it's paces on a few more disks (all very rarely defragmented before, if at all).
I observed one similar case though not as pronounced, also perfectly fine after a second run.
My conclusion is, that under certain circumstances (maybe especially when a lot of optimization work is required) MyDefrag can get its volume map wrong. Unfortunately I can not think of any other way of helping to pinpoint this behavior than switching on debug logging on any future attempts.
You might like to file my report under 'anecdotal' until I come up with some more tangible data.
In any case, I am very grateful for your work on MyDefrag. Thanks.