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recover sd card data with linux and gddrescue - 22 Jun 2010

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Just to be clear about the setup, I'll be using Debian 5 Linux and an 8 GB SD card with a SD to USB adapter over a USB 2.0 link.

gddrescue is included in the main Debian and Ubuntu repos, so in my case the install was just apt-get install gddrescue.

Plug in your sd card and watch dmesg for the sd card. Mine was added to /dev/sda as one can see from the following output:

[ 2540.580007] usb 5-4: new high speed USB device using ehci_hcd and address 2
[ 2540.776619] usb 5-4: configuration #1 chosen from 1 choice
[ 2540.781484] scsi1 : SCSI emulation for USB Mass Storage devices
[ 2540.781939] usb 5-4: New USB device found, idVendor=090c, idProduct=6000
[ 2540.781947] usb 5-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 2540.781953] usb 5-4: Product: USB2.0 Card Reader
[ 2540.781957] usb 5-4: Manufacturer: Generic,   .
[ 2540.781961] usb 5-4: SerialNumber: 12345678901234567890
[ 2540.781977] usb-storage: device found at 2
[ 2540.781980] usb-storage: waiting for device to settle before scanning
[ 2545.780245] usb-storage: device scan complete
[ 2545.781307] scsi 1:0:0:0: Direct-Access Generic 6000 PQ: 0 ANSI: 0 CCS
[ 2545.783697] sd 1:0:0:0: [sda] 15855616 512-byte hardware sectors (8118 MB)
[ 2545.784973] sd 1:0:0:0: [sda] Write Protect is off
[ 2545.784983] sd 1:0:0:0: [sda] Mode Sense: 4b 00 00 08
[ 2545.784988] sd 1:0:0:0: [sda] Assuming drive cache: write through
[ 2545.787318] sd 1:0:0:0: [sda] 15855616 512-byte hardware sectors (8118 MB)
[ 2545.787949] sd 1:0:0:0: [sda] Write Protect is off
[ 2545.787958] sd 1:0:0:0: [sda] Mode Sense: 4b 00 00 08
[ 2545.787963] sd 1:0:0:0: [sda] Assuming drive cache: write through
[ 2545.788050] sda: unknown partition table
[ 2545.795255] sd 1:0:0:0: [sda] Attached SCSI removable disk</code>

While logged in as root (or using sudo) make a copy of the sd card: ddrescue [/dev/device] [recovery image output] [logfile]

Now we will also need testdisk, so install that Debian or Ubuntu: apt-get install testdisk

Testdisk can do some pretty cool stuff, but we are more interested in one of the subpackages it includes, photorec.

Now using photorec, let's recover some photos: photorec /d [photo output dir] [recovery image output file from before] And navigate through the menus and get your photos back. Usually the sd card is formatted in NTFS.


390 words. Post tags: gddrescue, data, and recovery.

Post content is written by Jason Zerbe and licensed CC BY-NC 3.0.