Re: [Bug-ddrescue] Suggestion: Image size vs. source size sanity check

[Burkart Lingner]

Hi Antonio!

> a) The logfile does not currently store the size of the input drive.

Unless I'm mistaken it (implicitly) does. Just add the "pos" and "size" 
values of the last line. For me that works regardless of whether I 
aborted the imaging process after a few second or whether the imaging 
process was completed.

> b) Sometimes, or always on some systems, ddrescue can't determine the
> size of the input drive beforehand.

In that case a comparison obviously won't be feasible but that doesn't 
mean it shouldn't be available whenever the input drive's size actually 
can be read.

> c) Some machines have two or more identical drives installed, which
> report the same size).

Right, but again I don't see how that renders the comparison useless. 
After all, the suggestion is merely to warn the user if there's a 
mismatch between sizes which means there's quite a good chance that the 
user made a mistake. Differently put, it would help the user to not make 
one particular mistake; it wouldn't prevent him from making any mistake 
imaginable.

In order to prevent a mix-up between same-sized disks it would indeed be 
required to save a serial number or something similar to the logfile. 
Since that could create incompatibilities I understand why you don't 
want to do it. However, the beauty of my suggestion is that it doesn't 
require any such change and still adds one layer of protection from user 
mistakes.

Bye, Burkart