In the midst of other activities around my hard drives, I realized one of my old backup drives has suffered some damage. Not all of the files are readable.
I have more recent backups, so there's nothing catasrophic here, but before I jettison this drive I'd like to get off of it what i can. I have another of the same size that's empty, and I could just copy the whole drive to it, but I need a tool that's robust in the presence of errors.