[Bug-ddrescue] GDDRescue - suggestion immediate and appended image files for fast first data retrieval.

[wilsonstreet]

Hi Antonio,

Yet another thought.
Please forgive me for a bit of a barrage of suggestions,
but I have saved a few projects up for using Gddrescue with,
and while I am doing them I am having some thoughts.
Please understand that I am not thinking that these will be
done soon,
I am just writing them while I think of them,
so the development team can pick what ever (if any) they
want to do.

Suggestion
==========

It is possible for the user to do several passes to
progressively increase the amount of data that is retrieved.
In deed, that is what the algorithm of the program does,
even within a single run of the program.
The objective of the program is to get maximize the amount
of good data as soon as possible - later returning to the
more difficult areas.

It is observed that some runs can take many many hours or
even days.

In some circumstances, it may be important to get usable
data ASAP, or get examples of data ASAP.
The file checking utilities can not be run till an image is
completed.
However a completed image, is currently not generated till
the run/pass is complete.

It might be possible for Gddrescue to create intermediary
image files, after predetermined time intervals or
increments of data extracted.
These could all be appended/merged (e.g. possibly using a
similar method to retrieval from several sources) after the
complete retrieval of data to make a single complete image.

The advantage that results from the intermediary (split)
images, is that the user is able to attempt to extract files
from the intermediary images, which might be important to
help get their systems returning to normal faster. It also
would help them get an idea of how badly damaged the data
is.

This approach may possibly be achieved by using the method
that can get data from prioritized areas of the disk first,
just using a scenario where the disk is divided up into
consecutive areas, to make "sub" images.

Currently a user who thinks of doing this, might be able to
manually set up the commands to do it.
But it might be more user friendly to have the program do
it.


Yours
Al