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

On 04/05/2021 21:30, imschmeg wrote:
> On Tue, 4 May 2021 14:35:28 -0400
> imschmeg <[email protected]> wrote:
> 
>> On Tue, 4 May 2021 20:10:30 +0200
>> Denis Corbin <[email protected]> wrote:
>>
>>> On 04/05/2021 02:25, imschmeg 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 would increase verbosity (-v option) to have more information
>>> about what's going on during the different backup.  
>>
>> I will do that next.  
> 
> The problem appears to be solely with --on-fly-isolate.  I cannot
> reproduce the case I reported previously of getting the same result with
> -C instead, hence I probably misread my results (scrolling back in a
> terminal window has it pitfalls).  Using the -va verbosity option
> doesn't show any significant differences.
> 
> In other words, a command line like this:
> 
>> dar -c ./full --on-fly-isolate ./fcat --fs-root ./sub --delta sig
> 
> produces a tiny catalog (fcat) that is too small to contain deltas.
> However, running this afterwards:
> 
>> dar -C ./ccat --ref ./full --fs-root ./sub --delta sig
> 
> produces a larger catalog (ccat) with deltas.  Here are the sizes of
> the produced files:
> 
>    199277 ccat.1.dar
>       315 fcat.1.dar
>  34147102 full.1.dar
> 
> I saw your more-recent email about reading "Binary delta options usage
> and best practices".  I don't see anything there that suggests that
> catalogs created with --on-fly-isolate are different from those created
> using -C.
> 

Well, this was however in the documentation:

extract from the "--delta sig" description:
 Delta signature transfer is not possible for on-fly isolation, you
 need to do normal archive isolation to obtain an isolated catalogue
 with delta signatures.

and as reminder:

extract from the "--on-fly-isolate" desciption:
  Due to command-line exiguity, it is not possible to change compression
  algo nor slice size for the on-fly isolation. If you need a more
  complicated isolation, either look for a GUI over libdar, or do a
  normal (= not an on-fly) isolation operation.

Cheers,
Denis
> 
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> 
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