ddrescue strange read behaviour

[Marco Marques]

Hi,
 I have been accompaning the ddrescue util for a long time but only  
recently I have found some strange behaviour.
 Using the 1.24 version via AUR,  although sometimes I use the 1.19 ...

 In a nutshell, I am trying to rescue a SATA HDD ( already being  
marked by SMART in BIOS startup as failing) but I am having a bit of  
trouble to
recover data from it ...
 I have 2 different SATA controllers ( Intel and JMicron ) , and the  
results are and behaviour are different for each, with this particular  
HDD.

 Executing ddrescue with something simple as :   sudo ddrescue -d -O  
/dev/sdd /mnt/mk/recover recover1.map 

 In the Intel once a bad read sector is found I get several "Kernel  
ATA" errors and ddrescue continues to try to read.
 Despite the fact the HDD is now "offline and out of the system",  
ddrescue tries to continue with no sucess.

 In the Jmicron controller I get different situation :      
 Although still getting the same "Kernel ATA" errors but now ddrescue  
aborts with :
 "ddrescue: Unaligned read error. Is sector size correct ?"
 In the 1.19 version I get a different error:  Something like  
"ddrescue: unable to read input medium. "
 So in order to proceed I have to completly shutdown the system in  
order to access the HDD and proceed with the data recovery .
 ( Rebooting does not allow the system to recover access to the HDD ...)
 Any comment on the different controller behaviour ?

 With this specific HDD I did found some other strange behaviour  
where the -i flag was being ignored ...
 In one of the trials I call the "-i 500GiB" but ddrescue simply  
ignored it as it started to read from a lower value
 ( I confirmed it several times in the ddrescue -vv output as being  
the correct value) .
 Although I did not defined the "-s " flag  ...
 Is the "-s" flag mandatory ?

 Although I understand that the ddrescue output is for the running  
operation only,
 Before ddrescue aborts I get "read errors: yyy " but in the next  
ddrescue call it becomes 0 .
 it would be useful to have some kind of totaliser (failed , read  
error ) as also  have some kind of human readable info
( number of opening tries to the file )  in the mapfile related to  
previous ddrescue calls .

 Thanks in advance
 Marco Marques