Hi, I'm running into a bunch of problems on Linux 4.4 trying to recover a partition from a broken PATA harddisk, which fails only on a limited set of sectors, but stops responding after trying to read any of them. Unfortunately ddrescue 1.20 doesn't seem to support this situation very well :-(
The recently added -J flags *looks* like it should help in this situation -- but it turns out it doesn't really work for me :-( First of all, it never actually fails the verify. I suppose that's caused by the kernel's block caching -- however, neither --direct-input nor using a raw device work on my system: in either case, all reads fail immediately without ever even going to the actual disk. No idea what's wrong with it :-( But even if the verify worked in principle, it seems of limited use in its current form. For one, AIUI it only works when there was already a successfull read in the same run of ddrescue; while a failure on the first attempted block will still cause ddrescue to mark the rest of the disk as failed? Also, it seems to me that verify failure is handled like a write error on the output file -- which means it will never put information about the failing cluster in the log file? For now, I'm working with -X, which is somewhat helpful. It's a rather manual process though, as it puts the actual failed cluster in the log file, but nothing after that -- so the next attempt (after a power cycle) would always continue with the next cluster: there is no way to automatically skip a bigger chunk. (I'm working around this by setting a large cluster size, which sometimes does and sometimes doesn't skip enough, depending on whether the failure was far from the end of the cluster or not...) Also, -X only works for the first pass (copy) -- it looks like proceeding with trimming/scraping after that will be an even more manual process... Any suggestions how to address these problems? -antrik- _______________________________________________ Bug-ddrescue mailing list [email protected] https://lists.gnu.org/mailman/listinfo/bug-ddrescue
