Inconsistent manual defrag - move files to end of drive

[askitee]

Platform - Windows 10

Device - Western Digital 3TB External USB connected HDD

Issue - The option to manually move files to the end of the drive will move all files chosen on occasion, but mostly only some.

Steps:

1. Open Defraggler with "Run as Admin" or without
2. Select Ext HDD
3. Chose Analyze
4. Using bitmap on screen, select a square
5. In the file list below right click - choose "highlight folder"
6. Right click again and chose "Check highlighted"
7. Rick click and choose "Move checked to end of drive"
8. Defraggler will show the progress listing the files it is moving and the bitmap shows the reads (Yellow) and writes (Green) in the bitmap screen
9. a percentage of the time it moves all files selected, other times a subset, at times 1 and on occasion none
10. Ditto if I choose to not check the files highlighted and instead choose to "Move Highlighted to end of drive"

Restarting Defraggler as admin "cleans up the process" but over time it recurs.

Q1. What is the file select limit in this screen - I am working on thousands of small files and wonder if I am exceeding the file select limit

Edited February 13 by askitee

[Willy2]

Yep, that's one of the remaining "weak spots" in the program code. I have experienced the same thing many times over. I don't know whether or not there is a solution for this. And whether the developers are willing and able to fix this "weak spot" in the program code.

One also has to keep in mind that there multiple programs (including Windows itself) that also regularly read and write data from/to disk. And that can/will interfere with Defraggler as well.