Hey Folks:

I was trying to save a file to floppy for the first time. I successfully formatted the disk, wrote a DOS filesystem with /sbin/mkdosfs and mounted the drive. I read somewhere that to save to floppy I would have to issue this command:

cp filename /dev/fd0

I blindly followed this advice, and (as you would expect)overwrote /dev/fd0.

What should I now do? Is there any way for me to retrieve the /dev/fd0 as it once was before the overwrite? Am I screwed? I realize that this is the newbiest of newbie questions. Thanks for any help!!

davey

I don't understand what you think you did. cp file /dev/fd0 will not do anything to to the device /dev/fd0. What you did was you wrote over the bootsector of the floppy. So you can't mount the floppy now without formatting it again.

Basically you just trashed the disk but the drive is OK.

You need to reformat the floppy. That's the only thing that's broken. But don't try the same with a hard disk.

What you did and why it was wrong? /dev/fd0 is your first floppy, yes. But you can't write directly it. The thing is that floppy (it's the same with hard disk) is organized in a special way. First there's a 'header' telling which type of floppy is it etc and then comes the area for files. You can't also write distrectly to it, file area is also organized - into filesystem. Filesystem data tells where which file is places, file names and so on.

To make filesystem accessible the mount command is used. The system scans the media and reads filesystem informations and other special data. When you're copying a file to mounted filesystem, the OS modifies the filesystem structure the right way to make teh new file appear.

One more thing...formatting builds the filesystem structure.

So, the right sequence is:
mount -t msdos /dev/fd0 /mnt/floppy
cp filename /mnt/floppy