Originally Posted by fenstre
The first step is to not boot the phone until you get a dump of your data partition. Booting to a custom recovery is okay--a full Android boot is not.
In recovery (using the ADB shell), umount data and get a dump of the data partition (/dev/block/mmcblk0p37) using "dd". Since you can't write to the data partition while making its dump, you'll need to write to /system. Since /system isn't very big, you'll need to do the dump in pieces of about 350 MB each (depends on how much free space you have in /system).
The "dd" parameters you'll need are "bs" to speed things up, "skip" to tell it where to start the chunk, and "count" to determine how big the chunk is. Since /data is 25.6 GB, you'll need to do this 60-70 times, and after each chunk, use "adb pull" to copy the chunk to your computer. When you have all the chucks, reassemble them and make sure it's the same size as /dev/block/mmcblk0p37. Make sure it's a valid ext4 filesystem. Then you can start using data recovery tools.
So put your money where your mouth is and do it.
That sounds like something, first of all thanks for your input!
But how should i run this command without booting into android (I'm in clockwork-touch recovery, but doesnt seem to work)? This command works (when booted into android), i've tried it with 'dd', so i guess thats the correct way!
=> If i have to boot into android anyway to do this, i would also have an OTG plus USB-Stick (32GB), then i could do it in about 2 parts to save it directly to the usb-stick. Would that be the better aproach instead of writing it to the /system? because i don't know what action writes to the /sdcard
Just to clarify, i have to execute the following command one after the other(?) :
$ dd if=/dev/block/mmcblk0p37 bs=367001600 count=1 skip=0 of=/system/chunk1.img
adb pull /system/chunk1.img .
$ dd if=/dev/block/mmcblk0p37 bs=367001600 count=1 skip=1 of=/system/chunk2.img
adb pull /system/chunk2.img .
$ dd if=/dev/block/mmcblk0p37 bs=367001600 count=1 skip=2 of=/system/chunk3.img
adb pull /system/chunk3.img .
Do i have to make something special that i can reassemble them later or are there programms out there for that problem?