@Andreas Klauer a huge THANK YOU for taking the time to review my issue. I really appreciate your help. Sincerely, David Mitchell On Mon, Sep 4, 2017 at 11:49 AM, Andreas Klauer <Andreas.Klauer@xxxxxxxxxxxxxx> wrote: > On Sun, Sep 03, 2017 at 11:35:25PM -0400, David Mitchell wrote: >> I really do NOT remember running the --create command. > > There is no other explanation for it. It has happened somehow. > >> The pictures over 512k don't display correctly. > > So not only/necessarily a wrong data offset, but also wrong drive order. > >> At this point I'm hoping for help on next steps in recovery/troubleshooting. > > 1. Use overlays. > > https://raid.wiki.kernel.org/index.php/Recovering_a_failed_software_RAID#Making_the_harddisks_read-only_using_an_overlay_file > > That way you can safely experiment and create RAID with > different settings. (Use --assume-clean and/or missing) > > 2. Check first 128M of each drive (your current data offset). > See if you can find a valid filesystem header anywhere. > That way you could determine the correct data offset. > > 3. Find a JPEG header (any known file type, like a 2-3M file) > and look at the other drives for the same offset. You should be > able to deduce RAID layout, chunksize, drive order from that. > > Instead of 3) you can also simply trial and error with overlays > until you find a setting that allows photorec to find larger files intact. > > The resync might not necessarily have damaged your data. If the offsets > were the same and the RAID level was the same, and the drives were in > sync, a resync even with wrong settings would still produce the same data. > For XOR, a ^ b = c and b ^ a = c so switching the drives does no damage > provided you don't write anything else... > > Regards > Andreas Klauer -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
