[Bug-ddrescue] Reading certain sectors makes drive go off-line

[Veedar Hokstadt]

First many thanks to you Antonio for authoring such a useful application.

Consider a 1TB external USB Seagate drive that was extracted from it's enclosure and is now attached via SATA to my linux computer running ddrescue version 1.13

Try 1. Ran ddrescue -n. It copied 253GB with no errors but then  stopped and finished reporting one error with errorsize of 746GB. Then running fdisk -l no longer shows the source disk.

Try 2,3,4. Restarted the computer and ran ddrescue -T using log file from the first try. It makes very minimal progress, reports errors then the source disk goes off-line again. Running dmesg shows many errors. 

Try 5. Ran ddrescue  -d -n -T --input-position=500GB --output-position=500GB.  This succeeded copying 500GB with out errors at 35000 kB/s.

My question is do you think this is the best aproach?  My next try will be -input-position=300GB --output-position=300GB

Then I will try again changing the position to get as close as I can to the danger zone at the 253GB mark without the drive going off-line.

Regards,
Veedar