I use "badblocks" to test the disk before I'm commited to using it. The "-n" option does a non-destructive read/write test. Use the "-w" option to do a destructive test. You could also use the "fdformat" command to format and test the disk. Once the disk is known good, I use the "mformat" command to put a FAT file system on the floppy. This is equivalent to a DOS "quick format". The "mformat" command is part of the "mtools" utilities which makes DOS commands that run on Linux. That's why you see the mformat command referring to drive "a:". For those who love DOS, it's just like home.