High Water not working as expected

[RouterMonkey]

I just built up a server with 6 2T drives in an array.  I am migrating data over from another server (non UNRAID) via network file copies.  This involves about the copying of about 5 directories.

First few went as expected, to the point where each of the drives in the share failed to 1T (50%).  On the last directory copy, it moved back to the first drive, filling it to 75% (1.5T)  During the copy when copying date to the 2nd drive, the copy failed (issue with file on source) so I restarted from where it stopped by selecting the remaining files in the directory, copying into the directory on the UNRAID share.

When it hit 75% on the 2nd drive, it continued to copy to  that drive.  At about 1.56T, I stopped the copy.  I then selected the remaining files, and when I started the copy, it then started to use the 3rd drive.  Again, the when the high water mark was hit, it continued to use the drive.. So, again, I stopped and restarted, and again, it then proceeded to use the next drive.

I dozed off on the couch during that copy procedure, and when I woke up, the copy had finished, but it copied data onto the 4th drive instead of moving onto the 5th drive, filling the fourth drive almost completely (1.99T)

So, High Water seemed to work correctly till that last copy that I had to restart, copying selected files instead of the full directory.  3 times it filled a drive beyond the high water mark on the 2nd pass, although high water seemed to work just fine on the first pass.

Any ideas?

[JorgeB]

Looks like it should be working but please post your diagnostics: Tools -> Diagnostics, maybe something visible there, also and not directly related but note that you have to set the minimum free space for that share, to twice the largest file size you expect to copy, or you'll get out of space errors once the disks start getting full.

[RouterMonkey]

Thanks for that tip, and here is the diagnostic 

tower-diagnostics-20180621-0627.zip

[JorgeB]

Don't see nothing obvious, assuming your copying to \\tower\share it should work.

[RouterMonkey]

Yeah, and it seemed to be completely working as expected till I had to restart that last copy, copying files instead of directories... then it just didn't seem to be following the settings.  Very odd.