Re: gfloppy: Could not determine current format type

[Craig Orsinger <orsingerc epg-gw1 lewis army mil>]

On 14-Aug-00 Toralf Lund wrote:
>> [ snip ]
[snip]
> 
> Now, I finally got around to testing gfloppy again. This  time i tried some
> other
> tools, too. The commands I tested were:
> 
> 
>      mformat a:
>      fdformat /dev/fd0
>      fdformat /dev/fd0H1440
> 
> Of these, the first two failed - I've lost the message from mformat, but the
> fdformat
> one was
> 
>      Could not determine current format type: No such device
> 
> i.e. really the same thing as for gfloppy. The last command, however,
> formatted the
> floppy successfully, and (this is the interesting bit), after this, gfloppy
> started
> working as expected. This also goes for mformat and the other variant of
> fdformat.
> 
> I'm unable to reproduce the problem completely using a different floppy, but
> I'm also
> not able to fine one that's not (pre)formatted. I did get the fdformat error
> for some
> other the disks, though, one of which I know had been used previously as a
> tar archive.
> 
> The conclusion? Well, I'm still confused, but I think I've seen some
> indications that
> 'gfloppy' is actually only able to format floppy disks that are formatted
> already,
> which rather limits its usefulness.

        There are two types of "format" here, and that may be part
of the confusion. What Unix types think of as a format is the low-
level format of tracks on a magnetic medium. This type of format
is the one that "fdformat" creates. The other type of format is
what Unix types call a filesystem. In the MSDOS world, this was
called formatting (it's what you do when you use a 'format c:'
command in MSDOS or Windows). That's what "mformat" does (as well
as "mkfs"), so I'm not surprised that mformat failed if there was 
no low-level format on the floppy.

        OTOH, the fdformat command can't work unless it understands
what kind of medium you want to format. There are several possible
3-1/2" floppy formats (1.44M, 720K, 2.88M, etc). That's why only
the "fdformat /dev/fd0H1440" command worked - you told Linux to
low-level format the floppy as a 1.44M medium. I don't know 
whether fdformat can detect the format of a floppy that's already
been formatted, but if it does then you could use "fdformat /dev/fd0"
on a previously formatted floppy.

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Date: 15-Aug-00  Time: 10:45:13

Craig Orsinger                  (email: <orsingerc@epg-gw1.lewis.army.mil>)
Logicon Advanced Technology
Bldg. 8B28                      "Just another megalomaniac with ideas above his
6th & F Streets                 station. The Universe is full of them."
Ft. Lewis, WA   98433                   - The Doctor
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