Expected deduplication doesn't take place

[Igor Ostapenko <igor.ostapenko@gmail.com>]

Hi,

Could you please give me a clue what's wrong in the following situation.

I have a directory with static content. Subsequent tarsnapping looks to
be without deduplication, like content was changed (but it's not). I've
taken one of its files for testing:

$ # The first run
$ tarsnap -cvf .test.daily.20160119104958 .test
a .test
a .test/file.tar.xz
                                       Total size  Compressed size
All archives                               8.3 GB           3.5 GB
  (unique data)                            1.4 GB           622 MB
This archive                                10 MB            10 MB
New data                                    10 MB            10 MB

$ # The second run
$ tarsnap -cvf .test.daily.20160119105034 .test
a .test
a .test/file.tar.xz
                                       Total size  Compressed size
All archives                               8.3 GB           3.5 GB
  (unique data)                            1.4 GB           622 MB
This archive                                10 MB            10 MB
New data                                    10 MB            10 MB

$ ls -nl .test
total 10580
-rw-------  1 501  20  10830836 19 Jan 10:49 file.tar.xz

$ tarsnap --version
tarsnap 1.0.36.1


I have a bunch of *.gpg files in another archive where deduplication
works as expected.

It's a need to keep files in tar.xz. Anyway, conceptually I expected
deduplication in this case.


What do you think?