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Using RoboCopy I am copying large sets of files between storage devices and have noticed some strange behavior: On many occasions where the source and destination file are the same, RoboCopy sees the file as changed and copies it again. I have verified that the size and date of the files are the same. I am using the below command. The version of RoboCopy being used is from Vista/Windows 2008.

robocopy "W:\SourceFolder" "Q:\Destination Folder" /E /R:2 /W:5 /NP /LOG+:%1 /tee /fft /purge 

The /FFT switch used here often fixes this problem - but not here - (as in these pages addressing the same question: Robocopy falsely marks files as newer which itself refers to Robocopy Incorrectly Detects Files as Newer When Copying Between Different File Systems)

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1) Is there anything in the Robocopy output that might explain it? 2) As a test, for one of those "strange" files, if you delete the file at the destination, then run your Robocopy command to restore the file, do further uses of Robocopy still attempt to re-copy that file? – Kevin Fegan Jan 29 '14 at 23:41
The project is long over now. The original copy was done by robocopy so the basic answer to you delete and allow to copy again would be yes. I did not see any output other than "changed" – Brettski Jan 30 '14 at 3:52

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