newfs_msdos onto an image file

[Brian Candler]

On Sun, Jan 15, 2006 at 02:14:05PM +0100, Andrea Campi wrote:
> On Sun, Jan 15, 2006 at 12:49:51PM +0000, Brian Candler wrote:
> > Furthermore, why do I still have to pretend that the device is a 1440K
> > floppy disk? If I remove -f 1440 I get:
> > 
> > # newfs_msdos -h 64 -u 32 -s 256000 -a 125 -F 16 -b 4096 -c 8 /dev/md0
> > newfs_msdos: Cannot get number of sectors, Operation not supported
> 
> Just a wild guess: have you tried using fdisk? Pretending it is a floppy
> is probably working because real floppies don't have a partition table,
> whereas all kind of HDs in the DOS world have them.
> 
> Try creating just a single slice to cover all disk, and you should be
> ready to newfs it.

That doesn't really make sense to me - a filesystem exists within and
independent of any partition table.

I am creating an image of a filesystem, which as it happens I intend to
write out to a whole USB device, /dev/da0, but equally I could write it out
as the contents of a partition, /dev/da0s1. In either case the filesystem
would be the same.

Partitioning a loopback device is also not something I've tried. If I create
a partition table in /dev/md0, would I see /dev/md0s1? I guess I ought to.
But then I'd run newfs_msdos on /dev/md0s1, and would be back to square one.

Regards,

Brian.