Dear Antonio, Thank you very much for your answer, and suggestion to use the option '-a, --min-read-rate'. In between, I also tried to use the option -O which seemed suited, after noticing that the reading rate was dropping after a slow or bad area, without recovering unless I restart the process. Option -O apparently has the same effect of a manual restart, and indeed the backwards pass 2 finished during the night. Still a long way before the rescue ends, but one step at a time.
Best regards Bruno Le dim. 8 mars 2026 à 00:24, Antonio Diaz Diaz <[email protected]> a écrit : > Dear Bruno, > > Bruno Loup wrote: > > First, I would like to thank you for providing ddrescue tool to the > community. > > You are welcome. :-) > > > I noticed some very slow regions of the disk, that I would like to skip. > > I tried to use the -K (or --skip-size=) option, but it seems not to work > > during backward pass: > > You need to use the option '-a, --min-read-rate' in order to skip slow > areas. --skip-size just sets the size to skip, but does not enable > skipping > of slow areas. You may try something like '-a 50kB'. > > > http://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html#g_t_002d_002dmin_002dread_002drate > -a > <http://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html#g_t_002d_002dmin_002dread_002drate-a> > bytes > --min-read-rate=bytes > Minimum read rate of good non-tried areas, in bytes per second. If > the > read rate falls below this value during the first two passes of the > copying > phase, ddrescue skips ahead a variable amount depending on rate and error > histories. The blocks skipped are tried in additional passes (before > trimming). --min-read-rate is ignored in all passes but the first two. > If bytes is 0 (auto), the minimum read rate is recalculated every > second as (average_rate / 10). > > Best regards, > Antonio. >
