Reflinks by default
cp
is going to start defaulting to cp --reflink=auto
. From the manpage:
When --reflink[=always] is specified, perform a lightweight copy, where
the data blocks are copied only when modified. If this is not possible
the copy fails, or if --reflink=auto is specified, fall back to a stan‐
dard copy. Use --reflink=never to ensure a standard copy is performed.
KDE's KIO (and Dolphin file manager) will be doing this as well. Nautilus should follow suit. This might require changes in gvfs.
CC @cmurf