Re: [Bug-ddrescue] Version 1.15-rc1 of GNU ddrescue released

[Antonio Diaz Diaz]

Hello Dennis,

Dennis Juhler Aagaard wrote:
> First i like to thank you for a really great program. I use it almost
> daily. :-) I use it on Mac OS X both Snow Leopard and Lion, and i
> think i have found a bug. I just want to let you know before you
> consider releasing any staple version of the Version 1.15.

Thanks.


> When i try to recover harddrives larger than about 320Gb, the speed
> of the recovery goes from 20-40 mB/s down to merely 200kB/s after
> 320'ish Gb rescued data and the ddrescue program start consuming
> about 100% of processing power.

What is the filesystem of the destination drive? Some filesystems like 
NTFS3g seem to have problems writing large files.

What is the size of the logfile? Writing a very large logfile also could 
cause this problem.


> Firstly i thought it was because of a faulty drive, but now i am
> beginning to see a pattern here with several disks.

Do you mean "several source disks, but maybe the same destination disk"?


> I use the command sudo ddrescue -S -r3 /dev/diskXsX /PATH/DiskImage.dmg 
> /PATH/DiskImageLog.log

Have you tried without the '-S'?


> And that command is the one i have been using in a script for the
> last 2 years or so. so that shouldnt be the problem. I'll investigate
> further, but i am not the C-developer shark, actually i am just at
> the beginning of learning objective-c to wrap up your program in a
> nice GUI running on the Mac OS X.

Ddrescue uses 64-bit sizes, which means most probably slow recovery is 
because of some filesystem problem rather than a bug in ddrescue. 
Finding the cause surely does not require to be a C-developer shark. :-)


Best regards,
Antonio.