Trying to rescue data from a bad SD card

[Don Raikes]

> On Wed, 04 Mar 2009 21:21:43 +0100
> Eberhard Roloff <tuxebi at gmx.de> wrote:
> 
> ER> Damien Hull wrote:
> ER> > That's my problem. I can't use "dd" cause the device 
> isn't there.
> ER> > I think the system tries to create /dev/sdb but dd can't access
> ER> > it. 
> ER> > 
> ER> > 
> ER> > ----- Original Message -----
> ER> > From: "Bart Silverstrim" <bsilver at chrononomicon.com>
> ER> > To: "Ubuntu user technical support, not for general discussions"
> ER> > <ubuntu-users at lists.ubuntu.com> Sent: Wednesday, March 4, 2009
> ER> > 9:09:45 AM GMT -09:00 Alaska Subject: Re: Trying to rescue data
> ER> > from a bad SD card
> ER> > 
> ER> > Damien Hull wrote:
> ER> >> Thanks for the info. I installed and ran testdisk. No luck. It
> ER> >can't see the SD card. I think /dev/sdb is there but it can't see
> ER> >the card. Something like that. 
> ER> > 
> ER> > If the *device* is seen, you can try creating an image 
> with dd or 
> ER> > dd_rescue. Then you can run testdisk against the disk image.
> ER> > 
> ER> I would google for "free photo recovery" and then use 
> windows if you
> ER> 
> ER> fail on Linux. Sometimes this other OS also has its 
> merits, although
> ER> 
> ER> some Linux people will not want to know this.
> 
> I missed the start of the thread, so I may be repeating some 
> things, but
> I think there are a few things worth trying here:
> 1) Have you at some time previously been able to read the SD 
> card on the
> machine you are now trying? (there are two types SD and SDHC (High
> capacity) which are externally identical and the latter cannot be read
> in an SD only slot).
> 
> 2) What do you see if you have "tail -f /var/log/messages" 
> running in a
> terminal while you plug the card in.
> 
> 3) You could try a different machine or a USB reader.
> 
> -- 
> +------------------------+-------------------------------+---------+
> | James Tappin           | School of Physics & Astronomy |  O__    |
> | sjt at star.sr.bham.ac.uk | University of Birmingham      | --  \/` |
> | Ph: 0121-414-6462. Fax: 0121-414-3722                  |         |
> +--------------------------------------------------------+---------+
> 
Another thing to try after inserting the card is to run lsusb and see what it shows.  I know there is also a way using udevinfo to figure out what is being seen by the OS, but I don't remember how to do that part :-)

hth