Need to handle the exceptions/signals every time a disk read fails. With classic IO, you know when the read will happen. But with memory-mapped files, the exc

Need to handle the exceptions/signals every time a disk read fails. With classic IO, you know when the read will happen. But with memory-mapped files, the exception can happen at any time you are reading from the memory range. As for why disk reads fail, yes that's a thing. Less common on internal storage (bad sectors), but more common on removable USB devices or Network drives (especially on wifi).