Re: [Bug-ddrescue] Tip: Improving recovery chances with Seagate "F3" models

[Antonio Diaz Diaz]

Hello Scott,

Scott Dwyer wrote:
> I don't know exactly what you mean by a configure option, but I have had 
> success in adding conditional code (#ifndef __APPLE__) in the source to 
> check for and allow it to compile differently on a Mac (leaves out the 
> good stuff), since otherwise it would not compile.

I mean passing an option to configure as in:
  ./configure --enable-passthrough && make && make install

This way everybody else gets a normal ddrescue built.


> First, when using the passthrough option it is unable to tell the 
> difference between a drive and a partition. So sda1 or sda2 is seen as 
> just sda. I handle this by failing if the source ends with a number 
> instead of a letter. Not ideal, but the best I could come up with.

This is why I want a configure option. Strange behavior like what you 
describe is unacceptable in the normal ddrescue.


> When doing a direct ATA passthrough, it is possible to know the first
> sector of the error. Meaning that reading a 128 sector block and it
> returns with a read error, it will return the first bad sector in the
> block. This means that a bad sector could be marked right away, the
> sectors before it could be marked as unread as they would be known to
> be readable yet, and the sectors after could be marked as non-tried as
> it is unknown if they are good or bad.

Ddrescue already works like this. It is the kernel the one returning a 
total block failure when it finds a bad sector. I wish the kernel 
behaved better in case of read error. (Maybe some kernel version behaves 
as you describe. I don't know).


Best regards,
Antonio.