How synchronize ONLY ownership/group permissions?

I ran into a small problem where I used cp -Rf , but forgot the "p" (doh)

And well I need the permissions/ownership to transfer too, but this is a massive amount of files, and will take even longer to do so AGAIN.

So I am asking, is there a way to use rsync to synchronize ONLY ownership/pemissions from one dir to another without having to overwrite the entire file again, I have tried:

rsync -rpogt --existing /olddrive/root/etc/valiases /etc/valiases

Not working :-/

Thanks.

 

 

 

 

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