On Tue, 9 Oct 2018 09:52:00 -0600 Chris Murphy <li...@colorremedies.com> wrote:
> You'll be left with three files. /big_file and root/big_file will > share extents, and snapshot/big_file will have its own extents. You'd > need to copy with --reflink for snapshot/big_file to have shared > extents with /big_file - or deduplicate. Or use rsync for copying, in the mode where it reads and checksums blocks of both files, to copy only the non-matching portions. rsync --inplace This option is useful for transferring large files with block-based changes or appended data, and also on systems that are disk bound, not network bound. It can also help keep a copy-on-write filesystem snapshot from diverging the entire con‐ tents of a file that only has minor changes. -- With respect, Roman