Created attachment 209961 [details] adf-image of an empty floppy disk It looks like an old bug - see http://linux-m68k.vger.kernel.narkive.com/SGapOozl/linux-and-amiga-floppy-images IMHO it is common for all Intel i386, x86_64 kernels. So mount -t affs -o loop image.adf /mnt works for read, delete, but not for writing. :(