Filed Under (LG Android Phones, LG Phone Problem and Solution) by lg-phones on 25-12-2012

The Preamble:

  • Did you delete all your SDCard data of your LG Nexus 4?
  • Are you pissed because no one told you before you unlocked your bootloader what would happen?
  • Did you lose valuable pictures of cats doing wondrously funny things?
  • Well now there’s a convenient new way for you to get that data back Buckaroo!

The Problem:

Internal Memory doesn’t mount as a drive like external memory does. External memory would allow you to use data recovery tools that scan for deleted files and return them to a usable state. These tools work because most operating systems don’t go through and set all of those 1’s and 0’s to just 0’s when you delete a file. Usually the operating system will just delete the reference pointer in the index that says that a file exists with such-and-such name and it’s located at this position on the hard disk / memory location. There are destructive delete tools out there that will overwrite the spot of a deleted file multiple times to discourage recovery in just this manner. The issue is that data recovery tools need an actual mounted drive in order to dig deep and unearth those funny pictures of cats you so tragically deleted by accident. These newest batches of phones don’t have external SDcards which are super easy to mount as drives. Internal memory mounts as MTP/PTP which is not treated as a mounted drive and cannot be scanned by these data recovery tools. But, cry no more cream-puff!

The Process:

We will be using a Windows 7 machine to:

  • back up the entire internal memory partition to your computer as a single, massive .RAW file,
  • convert the .RAW file output to a VHD,
  • mount the VHD as a disk in Disk Manager,
  • scan the attached VHD volume for files that have been deleted and recover them,
  • ?
  • profit!

The Requirements:

  • A rooted LG Nexus 4 Android phone
  • BusyBox installed on your LG Nexus 4
  • Cygwin installed to [c:\cygwin] with pv and util-linux from the repo. Make sure to open Cygwin once to make sure that the /bin folder is created. Also, I made a folder at [c:\cygwin\nexus] to put the exported .RAW file,
  • Netcat (download the ZIP file and extract nc.exe to [c:\cygwin\bin]),
  • ADB (make sure adb.exe is in your path),
  • USB Debugging enabled on your LG Nexus 4,
  • VHD tool from the mighty M$. Put the VhdTool.exe file in [c:\cygwin\nexus],
  • Piriform Recuva or your favorite data recovery tool,
  • A calm sense of peace and serenity that you will get your files back

The Work:

  1. Identify which block/partition you want to recover. For our purpose here we are seeking to recover the userdata partition: /dev/block/mmcblk0p12
  2. Turn on your LG Nexus 4
  3. Connect your LG Nexus 4 in ADB mode
  4. Unlock the screen.
  5. Open a Cygwin terminal and enter (This assumes your BusyBox installation is at [/system/bin/busybox]. It may be at [/system/xbin/busybox]):
    • adb forward tcp:5555 tcp:5555
      adb shell
      /system/bin/busybox nc -l -p 5555 -e /system/bin/busybox dd if=/dev/block/mmcblk0p12
  6. Open another Cygwin terminal and enter:
    • adb forward tcp:5555 tcp:5555
      cd /nexus
      nc 5555 | pv -i 0.5 > mmcblk0p12.raw
  7. Run around the house a few times. For 32GB internal memory this is going to take 3+ hours. That’s a lot of running. When it’s done
  8. We need to convert the .RAW file to a virtual hard drive. VhdTool.exe basically just puts a VHD footer on the end of the .RAW file. Open a Windows command prompt, go to [c:\cygwin\nexus], and type:
    • VhdTool.exe /convert mmcblk0p12.raw
  9. Now we need to mount the VHD in Windows. Select the Start button–>right-click Computer–>select Manage.
  10. Select Storage–>Disk Management.
  11. In the menu select Action–>Attach VHD.
  12. For Location enter [c:\cygwin\nexus\mmcblk0p12.raw] and select the OK button.
  13. Right-click on the name (e.g. "Disk 1") to the left of the Unallocated space and select Initialize Disk.
  14. Select the GPT (GUID Partition Table) radio button and select the OK button.
  15. Right-click on the Unallocated space and select New Simple Volume…
  16. In the Wizard select Next>, leave the default for the volume size, select Next>, select a drive letter (e.g. K), select Next>, MAKE SURE to select the ‘Do not format this volume’ radio button, select Next>, select Finish.
  17. A box will pop up asking you to format the drive. You DO NOT want to format the drive at this time.
  18. Right-click on the RAW space and select Format… MAKE SURE to change the File system to FAT32. Set the Allocation unit size dropdown to ‘Default.’ MAKE SURE that the Perform a quick format checkbox is CHECKED. You do not want to overwrite the entire new drive with all zeroes (0’s) and destroy your data. Quick Format means that it will only attempt to destroy the index for the drive by establishing a new index. Without this box checked the Windows operating system will write zeroes (0’s) across the entire volume, potentially destroying your data. Select the OK button.
  19. A box will pop up saying that Formatting this volume will erase all data on it. That would be doubly true if you actually didn’t check the ‘Perform a quick format’ checkbox. Double check that you actually did check the box and select the OK button. (Don’t worry. This essentially leaves the volume in the exact same state that your phone’s internal memory is living in right now: there is data on the drive…you just can’t see it. It’s coming back, I promise!)
  20. Open the Piriform Recuva application. In the wizard select the ‘Next >’ button. Select the ‘Other’ radio button and select Next >. Select the ‘In a specific location’ radio button and enter: k:\ (assuming K is the drive letter you chose…) Select the Next > button. Select the Enable Deep Scan checkbox. This is the magical setting that finds files that have been deleted…but not really deleted. Select the Start button.
  21. The application may take about an hour to do the ‘Deep Scan.’ It’s time for more laps around the house! Once the application has returned its results you can choose which files to recover using the checkboxes. Select the ‘Recover…’ button and choose the location to which you wish to output your files.
  22. ?
  23. Profit!

Good luck!

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Anonymous on 25 December, 2012 at 2:08 am #

I forgot to mention, but run commands inside android as superuser or may fail (just after adb shell):
adb forward tcp:5555 tcp:5555
adb shell
/system/bin/busybox nc -l -p 5555 -e /system/bin/busybox dd if=/dev/block/mmcblk0p12

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