Hello, this is not a bug report but a request for new feature for gddrescue, "update mode". I use gddrescue a lot, to copy boot images to USB disks. I know I can use old "dd" but I prefer gddrescue...
I miss a mode to update USB disk, it should work like this: 1) read block from destination disk 2) compare date from destination disk with source image 3) Are data the same? Then skip and continue go to step 1 4) otherwise do an update, write data from source disk to destination disk and go to step 1 Advantages? Reads are faster than writes. USB disks have limited number of writes they can accept (TBW parameter in SSD). I believe that "update mode" can speed up some updates and lower number of blocks those have to be written. With regards, Petr