ROBOCOPY: ERROR 87 (0x00000057) Changing File Attributes

Warning - this post does not really offer a solution to the root problem :)

I ran into this when trying to mirror one external USB hard disk drive with a NTFS file system to another external USB hard drive with exFAT file system:

2024/12/12 08:18:03 ERROR 87 (0x00000057) Changing File Attributes <source file pathname>

The parameter is incorrect.

Waiting 30 seconds...

and it keeps repeating. However, it turns out that the problematic file actually has been copied over, and the error happens when ROBOCOPY tries to modify some attribute of the SOURCE file.

Since this was an error after the copy operation, my quick workaround was to simply force ignoring failures in updating attributes of the source file without getting too deep into it:

ROBOCOPY  "<SOURCE DIR PATH>"  "<TARGET PATH>" /MIR /R:1 /W:1 /MT /V

Of course, why ROBOCOPY was failing to update the attributes of the SOURCE file needs deeper investigation some day! Anyway, here are the descriptions of the switches used:

/MIR: Mirror Directory Structure

The /MIR switch ensures the destination folder mirrors the source folder. This includes copying new files, updating modified files, and removing files in the destination that no longer exist in the source.

/R:1: Retry Once on Failure

By default, ROBOCOPY retries a failed copy operation 1 million times. The /R:1 switch limits this to a single retry, saving time when dealing with inaccessible files.

/W:1: Wait One Second Between Retries

The /W:1 switch sets the wait time between retries to 1 second, significantly reducing the default 30-second wait time.

/MT: Multithreaded

The /MT switch enables multi-threaded copying, meaning it utilizes multiple CPU threads to simultaneously transfer files, significantly speeding up the copy process, especially when dealing with large amounts of data. A default of 8 threads are used, which can be overridden using, for example, /MT:16 for 16 threads.

/V: Verbose

The /V switch stands for "Verbose". When used, it causes Robocopy to output additional information during the copy process. Specifically, it displays the names of the files being copied, along with any skipped files, and other details such as the status of the file copying operation.