Re: [Bug-ddrescue] Bug-ddrescue Digest, Vol 102, Issue 4

[Scott Dwyer]

On 7/11/2014 12:42 PM, William wrote:
> ddrescue -vvv -d -c 1 -r1 --skip-on-first-err   /dev/sdb 
> Samsung-1500GB.dd Samsung-1500GB.dd.log 
Interesting. You are reading one sector at a time and skipping. I have 
not yet tested that combination. The advantage of skipping out of the 
bad areas early on to get more good data first, but never read any 
sector twice. Makes for slower reads of the good data, but overall would 
still be faster.

> PS: Why not creating a patch that only runs forwards with just one 
> pass, at least when using --no-retry; something like "-n 
> --only-forwards"? Would be hard to create it?
Let me understand what you are proposing. You would like an option to 
stop after pass1 (would also include option to stop after pass2). This 
option(s) would effectively stop the rescue after pass 1 or 2, before 
getting to the slow no-skip pass. When ran again without the option, 
ddrescue would continue from that point on (kind of like the no-trimming 
and no-splitting options). If this is what you would like, I am not sure 
how hard it would be without looking into it more. If it is doable, it 
could make it into the next patch version.

PS: If you are running Linux, have you tried the sgio_passthrough patch 
(I don't see it in your commands)? It can be used along with the 
features patch. There has been great excitement about the features 
patch, but I have heard nothing from anyone about the passthrough patch 
which came out beforehand. It would appear that no one is excited about 
something that can make ddrescue process errors 5 times faster.

Scott