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7

Rescue data from corupted FAT32 micro SD card

rated 0 times [ 7] [ 0] / answers: 1 / hits: 8104 / 1 Year ago, thu, february 16, 2023, 10:00:34

I used it on android and it just stopped working. I want to extract data before I format it. Here's the output of sudo dosfsck -w -r -l -a -v -t /dev/mmcblk0p1:

fsck.fat 3.0.26 (2014-03-07)

fsck.fat 3.0.26 (2014-03-07)

Checking we can access the last sector of the filesystem

Boot sector contents:

System ID "android "

Media byte 0xf0 (5.25" or 3.5" HD floppy)

       512 bytes per logical sector

     32768 bytes per cluster

        32 reserved sectors

First FAT starts at byte 16384 (sector 32)

         2 FATs, 32 bit entries

   2022912 bytes per FAT (= 3951 sectors)

Root directory start at cluster 2 (arbitrary size)

Data area starts at byte 4062208 (sector 7934)

    505668 data clusters (16569729024 bytes)

16 sectors/track, 4 heads

         0 hidden sectors

  32370688 sectors total

Checking file /

/

  Contains a free cluster (2). Assuming EOF.

FAT32 root dir starts with a bad cluster!

Is it possible to save data? Thanks!

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tigehanc

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4 Years ago

answered 1 Year ago fenddy · Accepted Answer

Use ddrescue to make a copy of the SD card - you don't want to work off of the original.

You can use TestDisk or Autopsy to try recovering the filesystem or a tool like scalpel to carve files from the disk.

Here are some basic commands:

ddrescue

ddrescue is used in a similar fashion to dd. Namely:

ddrescue /dev/XXX /home/user/Desktop/copy_of_sd_card /home/user/Desktop/logfile

The logfile will store the information about any sectors it had trouble reading.

Source.

TestDisk

You can then use TestDisk to try to retrieve files from the image:

testdisk /home/user/Desktop/copy_of_sd_card

It has a wizard-like interface. as well. A full guide is here.

Autopsy

Autospy is a graphical interface over the sleuth kit. When you run it, it creates a web interface.

This site has a simple walkthrough on how to use Autopsy.

Also, see this