On 2019-02-16 3:08 p.m., Andrei Borzenkov wrote:

> 
> File size of "real" server.jar is not exact multiple of btrfs block size
> (4096) which causes the last extent to be "incomplete". btrfs won't
> clone extent in this case. You can trivially reproduce it by using the
> same size in the first case (although exact extent distribution may be
> different of course, in the worst case you get single extent which is
> sent in full):
> 
> 
> 
> dd if=/dev/urandom of=A/dir/server.jar bs=1024 count=34625
> 

Thank you.  I thought I had tested one where I changed the file size,
(by  altering the bs,) but I must have inadvertently created a file that
still divided by 4096, (or it got split into a second extent).