Re: ddrescue: new option, ""--compare-before-write", "check destination block content before write"

[Antonio Diaz Diaz]

Dr. Hinner EDV wrote:
> First of all Thank you very much for your work and your contribution!

You are welcome! :-)


> I'm about to write a backup system, it should be energy-efficient and fast.
> [...]
> So I'd like to suggest to introduce a new option "--compare-before-write".

Given that writing can be slower on some devices than reading, this may be 
an interesting feature. It all depends on how frequently a block (or a 
sector) is overwritten with the same data.

But this is a significant change because ddrescue currently opens outfile 
write-only. So I guess it will have to wait until after 1.26 stable is 
released in a couple weeks or so.


> I also wonder if SSDs do this check by themselves, in my opinion it
> would be smart to do because of wear, but it also takes some time.

I have no idea whether SSDs compare the data before writing it. (I tend to 
think they don't).


Happy new year to everybody!
Antonio.