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Date:      Mon, 2 Feb 2009 11:52:44 -0500
From:      William Bulley <>
Subject:   short-changed on SD card?
Message-ID:  <20090202165244.GB1012@dell1>

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Recently purchased a brand new 2.0 GB secure digital (SD) card.

When I plugged this into a USB dongle and plugged the USB dongle
into an available USB socket on my FreeBSD 7.0-STABLE system the
output from dmesg(8) reported this:

   da1: 960MB (1967616 512 byte sectors: 64H 32S/T 960C)

This is much closer to 1.0 GB than 2.0 GB so I at once wondered
if I had been scammed in my purchase of this brand new SD card.

Once I'd mounted /dev/da1s1 on /mnt, the df(1) command also reported
960 MB.  I then copied a 300+ megabyte file onto /mnt and then ran
the df(1) command again.  This time it reported 1.9 GB total and
1.6 GB available.  WHAT IS GOING ON HERE?  Am I going crazy?

Is this normal behaviour for a FAT16 formatted (raw/blank) SD card?

Is there something I can do using the fdisk(8) or similar command
to change the SD card so that it believes (and FreeBSD believes) that
it is truly a 2.0 GB card?

As I continued writing (large, multi-hundred megabyte) files to the
mounted SD card, the system eventually seized up and I had to reboot.
I expect this had something to do with my having crossed the 960 MB
boundary on this SD card.  Help!  Any ideas gratefully accepted.



William Bulley                     Email:

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