I used an amazing tool for data recovery a few months back, and now for the life of me I can't find it again. I thought it was rdd-copy, but that doesn't seem to be able to do a batch operation. The tool I used was kind of like a robust version of rsync, where you could give it a source directory and a target directory, and it would copy each file it encountered, except if it hit a bad sector, it would immediately shrink the "copy block" size down to a user-specified number, and try to copy tiny bits of the file at a time in sequence. After a certain number of tries, it would give up on that block, copy zeros instead, and move on to the next block.
Does anyone know what this tool is? I haven't found the right set of google terms to locate it. There are a lot of "bad sector" recovery tools out there, but most of them seem to be device-oriented instead of file-oriented (e.g. making a raw image of an entire drive), and I need to run it on a directory with a wildcard instead.