Robocopy DCOPY:DAT invalid paramter?

Question

I want to clone an sd card, trying to use robocopy. What's wrong with the following statement?

ROBOCOPY e:\ c:\backup /MIR /COPYALL /DCOPY:DAT

Output: Invalid Paramter #5 : "/DCOPY:DAT"

What works would be a /DCOPY:T. But why can't I use the :DAT options?

What does 'robocopy /?' produce for DCOPY? I am seeing some older references online that only describe a valid flag of 'T' for DCOPY. — Daniel K, May 25 '19 at 17:33
@DanielK you're right, the help menu only outputs the `T` flag for `DCOPY`. I true, how could I then achieve the same result that `DCOPY:DAT` would produce? Or is that already included in `COPYALL`? Unfortunately there are so many references that just state the dcopy:dat paramter... — membersound, May 25 '19 at 21:20

score 3 · Accepted Answer · answered May 25 '19 at 22:34

Knowledge base article 2646535 addresses this in passing:

The default Robocopy behavior in Windows 7 and in Windows Server 2008 R2 (in the released versions and the hotfixed versions) is the same as using the /DCOPY:DA option.

So /DCOPY:T on Windows 7 is equivalent to /DCOPY:DAT on Windows 10. The Windows 7 version simply doesn't give you the option to not copy extended attributes and alternate data streams.

Note that the KB article linked above describes a hotfix that gives Windows 7 the new command line options, but I recommend against using it unless you have a compelling need.

Robocopy DCOPY:DAT invalid paramter?

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