I think this has nothing to do with MD vs ZFS. The key issue is that I think it's crazy to tinker around with 'bad blocks' in the first place. A hard drive wi

I think this has nothing to do with MD vs ZFS. The key issue is that I think it's crazy to tinker around with 'bad blocks' in the first place. A hard drive with bad blocks that it cannot conceal from the end-user is broken and not to be trusted. Replace it.