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Date:      Mon, 2 Feb 2009 14:52:52 -0500
From:      Jerry McAllister <jerrymc@msu.edu>
To:        Jerry McAllister <jerrymc@msu.edu>, Mel <fbsd.questions@rachie.is-a-geek.net>, freebsd-questions@freebsd.org
Cc:        Jerry McAllister <jerrymc@msu.edu>
Subject:   Re: short-changed on SD card?
Message-ID:  <20090202195252.GA23080@gizmo.acns.msu.edu>
In-Reply-To: <20090202192720.GE1012@dell1>
References:  <20090202192720.GE1012@dell1>

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On Mon, Feb 02, 2009 at 02:27:20PM -0500, William Bulley wrote:

> According to Jerry McAllister <jerrymc@msu.edu> on Mon, 02/02/09 at 14:12:
> > 
> > I am a little lost here and haven't tried a lot on USB devices yet - 
> > though I haven't had these kind of problems.
> > 
> > But, after doing the fdisk stuff and before trying to mount, did you
> > do a newfs?
> > 
> > Another thing would be to try the old   
> >   dd if=/dev/zero of=/dev/da1 bs=512 count=1024
> > and see if it will write to it and wipe enough stuff to free it up.
> > Up the count if you think it makes any difference.
> 
> Thanks.  According to the newfs(8) man page it is used only for BSD
> style file systems (ufs and ufs2).  I am okay with the FAT16 formatted
> SD card, I'm just upset that I paid for a 2.0 GB card and ended up with
> what seems to be a 1.0 GB card.  I would be happy if I could make the
> SD card look like this:
> 
>    slice 1  2.0 GB (well, 1920 MB if you insist)
>    slice 2  <UNUSED>
>    slice 3  <UNUSED>
>    slice 4  <UNUSED>
> 
> And I thought I had done just that using fdisk(8).  But I must have gotten
> some of the "beg" and "end" paramaters set up wrong.

OK.    I thought you were trying to make a FreeBSD type slice on it, thus
the newfs thought.   It won't mount if it isn't newfsed and is FreeBSD type.

I suppose FreeBSD's fdisk will make MS types, but have never tried it.
But, if it will, then it will also do it after wiping the device with dd.    
After doing that, you should be able to just tell it to turn all the space 
on the drive in to one slice of whatever type it will handle.

////jerry



> 
> If the card is indeed 2.0 GB in size, and following in the style of the
> originally reported parameters of this card:
> 
>    da1: 960MB (1967616 512 byte sectors: 64H 32S/T 960C)
> 
> that is, 64 "heads", 32 "sectors per track", and 960 "cylinders",
> (this evidently from what the BIOS reports and understands) I had
> assumed that I could merely increase the cylinder count up to 1920
> and leave the head and sector information as it was.  But as I said
> earlier, this didn't seem to work.  I know I have to leave room at
> the beginning for the MBR or the like, but the tools are either too
> low level, or too high level, or my understanding of all this is not
> up to speed.  Why can't an SD card advertised (and sold) as a 2.0 GB
> card actually hold (approximately) 2.0 GB?  That is what bugs me...
> 
> I believe that FAT16 is capable of addressing a 2.0 GB disk drive, yes?
> 
> Regards,
> 
> web...
> 
> --
> William Bulley                     Email: web@umich.edu
> 



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