microSD card detected with wrong size/capacity

[The Small Box Admin]

This is most likely what it is:
http://www.sandisk.com/about-sandisk/press-room/press-releases/2010/2010-12-20-sandisk-secure-flash-memory-technology-to-power-new-cricket-unlimited-%E2%80%9Cmuve-music%E2%80%9D-wireless-service/

On Tue, Jul 7, 2015 at 2:13 PM, C M Reinehr via Linux-users <
linux-users at linux-sxs.org> wrote:

>  On Sunday, July 05, 2015 05:44:15 PM Lonni J Friedman via Linux-users
> wrote:
>
> > I've got a weird one here. A microSD card which came with a junky old
>
> > Android phone claims to be 4GB on its label, however there's some
>
> > weird marketing nonsense about how "3GB reserved for music". When I
>
> > plug the card into a reader attached to a linux box, its always
>
> > detected as a 1GB card:
>
> > [3181684.541224] scsi 10:0:0:0: Direct-Access Generic STORAGE
>
> > DEVICE 0207 PQ: 0 ANSI: 0
>
> > [3181684.541593] sd 10:0:0:0: Attached scsi generic sg7 type 0
>
> > [3181685.004787] sd 10:0:0:0: [sdg] 1934848 512-byte logical blocks:
>
> > (990 MB/944 MiB)
>
> >
>
> >
>
> > I'm guessing that there's something weird going on with the card that
>
> > hides 3GB from the OS somehow. Has anyone run into this before? Any
>
> > tips on how to unhide the missing 3GB?
>
> >
>
> > thanks
>
>
>
> I believe that this Wikipedia article may provide a clue:
>
>
>
>
> https://en.wikipedia.org/wiki/Secure_Digital#Storage_capacity_and_incompatibilities
>
>
>
> Per the article, a host o/s determines the capacity of an SD card by
> interogating the card for it's Card-Specific Data identification string.
> The article goes into some detail about the format of this string and
> different versions, but the important part is that the o/s knows the size
> of the card based upon the card provided CSD. In this case, I believe that
> the card intentionally is misreporting the size of the card.
>
>
>
> HTH.
>
>
>
> CMR
>
> --
>
> “Three millions of people, armed in the holy cause of liberty, and in such
> a country as that which we possess, are invincible by any force which our
> enemy can send against us. Beside, sir, we shall not fight our battles
> alone. There is a just God who presides over the destinies of Nations, and
> who will raise up friends to fight our battles for us. The battle, sir, is
> not to the strong alone; it is to the vigilant, the active, the brave.” --
> Patrick Henry
>
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