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Date:      Mon, 2 Feb 2009 14:27:20 -0500
From:      William Bulley <>
To:        Jerry McAllister <>
Cc:        Mel <>,
Subject:   Re: short-changed on SD card?
Message-ID:  <20090202192720.GE1012@dell1>

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According to Jerry McAllister <> 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.

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?



William Bulley                     Email:

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