On Tue, 9 Oct 2018 09:52:00 -0600
Chris Murphy <lists@xxxxxxxxxxxxxxxxx> 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
