On 03/10/2018 05:24 PM, Stephen Morris wrote:
I can't find the documentation any more, but I have found
documentation on how to use copy the create the target as a hard link
or as a soft link. It is possible I have incorrectly remembered what I
had read, or it is possible over time that the standard copy
functionality has changed and now you have to explicitly specify that
you want that functionality.
I'd forgotten the other system that works as you described: reflink.
"cp" supports a --reflink option, and on a few filesystems that
implement it (btrfs, OCFS2, maybe xfs and zfs, I'm unclear on their
status), you can create a CoW copy of a file.
Again, not standard behavior, not widely implemented, and relatively
new, but this might be what you were thinking of.