Re: why [Saved][D] instead of [Delta][D]?

On Mon, 3 May 2021 20:25:45 -0400
imschmeg <[email protected]> wrote:

> In another use of dar on a non-encrypted filesystem, I am using
> options --delta sig and --delta-min-sig-size 1M.  I have a full and a
> differential with that full as --ref, both with the same --delta..
> options.  However, when I list the differential's contents, all [D]
> files (those with computed deltas) in it are [Saved][D] instead of
> [Delta][D]. Why might that happen?
> 

I think this is happening because I am using --on-fly-isolate to build
a catalog, and then using that catalog as --ref for the differential
(sorry for not specifying this correctly above).  

I tried a simple test: in one scenario, I backed up a 32M file
without --on-fly-isolation and used it as --ref when backing up that
same file after appending a little to it, and the resulting
differential was small and showed the file as [Delta][D].  In the other
scenario, I did the same but with --on-fly-isolation, and used the
resulting catalog as --ref for the differential, and the resulting
differential was large and showed the file as [Saved][D], meaning it
had saved the whole thing again.

I repeated this using -C to create the catalog instead of
--on-fly-isolate, but there was no difference in behavior.  In both
cases, the catalog was way too small to contain delta signatures for
this one file (a 32M file backed up, the catalog is just a little over
300 bytes).

Do I need some other option to make sure that differentials that --ref a
catalog will use the deltas?  I thought the delta signatures would be
transfered to the catalog without the need of any additional options.
Just for kicks, I tried --include-delta-sig '*', but that didn't change
the behavior either.