Re: [Bug-ddrescue] Possible bug with ddrescue 1.7 and later.

[Antonio Diaz Diaz]

Hello Andrew,

Andrew Stuart wrote:
> Hi, first let me start by saying good job. Your software has been very 
> helpful in recovering a few bad hdds.

Thanks.


> I started experiencing problems with *really* bad drives after the 1.7 
> release. Although I have to admit, I have not gone back to 1.6 to prove 
> this was the case, are the log files compatible between these two versions?

Yes, see the chapter "Logfile Structure" in the ddrescue manual for details.


> I am using FreeBSD 7.0, and ddrescue 1.8. Everything works fine, up 
> until the hdd gives up the ghost and disappears. At this point ddrescue 
> does not stop, but continues trying to copy data, while marking it as 
> bad sectors, up to several hundred TB's of data before stopped, if you 
> don't keep an eye on it.

If FreeBSD makes dissapear the device from /dev while ddrescue haves it 
open, it seems like a bug in FreeBSD. An application cannot be 
constantly verifying if the OS has made its open files "dissapear".

Ddrescue also limits the rescue domain to the size reported by the OS. 
So, if ddrescue tries to read past the end of the drive it is because 
the OS didn't report the drive size. Does ddrescue report it is about to 
copy "an undefined number of bytes"?


> After powering down the machine and letting the hdd rest for a while, 
> trying to restart the recovery seemingly sits there doing nothing, when 
> using the log that believes its has achieved 200+TB's of data/errors.

Just remove from the logfile the lines following the last line marked as 
finished (+) and restart the rescue.


Regards,
Antonio.