[raydude]

I asked this question elsewhere but received no reply. I'm hoping you guys will have some ideas.

My daughter and son each got a K1 for Christmas. We bought Samsung 64GB SDCards to go in each. Installation was a bit of a pain since you need long finger nails or a small screw driver to push the card in all the way, but once they were set up, it was easy to format and use the cards.

I set them up as internal storage which, I suspect, causes them to be encrypted. About 20 days in, my daughter's SDCard died and became read only. I made a backup of it with linux dd and found that the master boot record is corrupt, but luckily the backup is good, so the card partitions are readable:

gdisk output

gdisk sdcard.dd
GPT fdisk (gdisk) version 0.8.10

Caution: invalid main GPT header, but valid backup; regenerating main header
from backup!

Caution! After loading partitions, the CRC doesn't check out!
Warning! Main partition table CRC mismatch! Loaded backup partition table
instead of main partition table!

Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: damaged

****************************************************************************
Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
verification and recovery are STRONGLY recommended.
****************************************************************************

Command (? for help): p
Disk debi_sdcard.dd: 125067264 sectors, 59.6 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 316E5963-9593-47BB-BE0D-7D6151DCFE85
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 125067230
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number Start (sector) End (sector) Size Code Name
1 2048 34815 16.0 MiB FFFF android_meta
2 34816 125067230 59.6 GiB FFFF android_expand

I suspect that the partition is encrypted and the data may be un-usable. But when my daughter found out that I may not be able to recover the data (she's done a lot of art) she cried, so I'm trying my damnedest to find a way.

My first attempt to recover the data was to dd the image directly onto the new card, but Android didn't recognize it as the card that had failed. I really thought that would work too. I think that happened because I had followed nvidia's suggestion and reset the tablet. I think that's when I blew any chance of getting the data back.

I have since installed the new card and formatted it.

Does anyone have any idea how -- or even if -- I can recover the data?

Thanks in advance.

[Golfdriver97]

Welcome to the forums. Maybe something like this will help: Does Linux have a chkdsk function? | Linux.com

Edit: found a couple others
http://askubuntu.com/questions/27784...ted-how-to-fix

http://unix.stackexchange.com/questi...-a-bad-sd-card

and a couple more ideas here: http://forum.xda-developers.com/showthread.php?t=367912

[raydude]

Thanks for the reply. I haven't found any thread anywhere that talks about mounting android partitions in linux. I guess that's what I'm looking for.

[Golfdriver97]

Thanks for the reply. I haven't found any thread anywhere that talks about mounting android partitions in linux. I guess that's what I'm looking for.

Sorry about the delay. Not sure myself, but I passed this along to someone who might have a better shot at helping you.

Linux user myself, but this kinda went over my head.

[raydude]

That's why I'm here. This is a complicated issue. I know a bit about linux, file systems, hardware and the like but android file systems, I know little to nothing there.

Thanks for forwarding my request, I really appreciate it.

[Rukbat]

If you used Android to mark the SD card for app storage, it's encrypted, and there's no way to recover anything from it (but you can still try - keep reading).

If you marked it for data storage, it's unencrypted, and the MBR, GPT and filesystem are irrelevant if you use PhotoRec to recover files from it. (It looks for blocks that look like files it recognizes - and it recognizes more file types than I do.) Instructions are at PhotoRec Step By Step. You'll be in a Linux command line window, so if you're familiar with Linux it should be trivial, if not the instructions will help. (Filenames won't be recovered - files will get generic names like file0001.jpg for a picture or file0002.mp3 for an audio file.)

If the card is encrypted, it can't hurt to try - PhotoRec doesn't write to the card, it only reads it, so if it fails, all you;ve lost is time. (And it takes a lot of time, even if the card is good but you're looking to recover deleted files - hours, at least.)

[raydude]

Thanks. I'm pretty sure it's encrypted. I should have set it up as data storage. Who knew a Samsung SD would go bad?

[Toltepeceno Delsur]

Thanks. I'm pretty sure it's encrypted. I should have set it up as data storage. Who knew a Samsung SD would go bad?

I would try to reformat it on a computer, using something like this:

https://www.sdcard.org/downloads/formatter_4/

just to make sure. I have had several episodes with my sdcard on my shield and once I thought it had gone bad but I formatted it on a computer and it was just marshmallow adoptive mode being wonky I think. You cannot just format it with a pc, the phone will still not see it, you need to format with this app or there are several more out there. I formatted it on the wife's pc and the phone could not see it but my mac could so I did a terminal command to format it to dos fat32. I have actually had to do it a few times, once because the shield got stuck in a boot loop and had to do a data reset.

[raydude]

I could not make any changes to the partition table on a linux PC, I'm pretty certain it was toast. I think it dropped to read only for some reason. The card is long gone and been replaced by Amazon. The new card works, but I was hoping to be able to read it for my daughter's sake. That doesn't seem possible now.

[Golfdriver97]

I could not make any changes to the partition table on a linux PC, I'm pretty certain it was toast. I think it dropped to read only for some reason. The card is long gone and been replaced by Amazon. The new card works, but I was hoping to be able to read it for my daughter's sake. That doesn't seem possible now.

I would suggest finding a way that can back all of her stuff up automatically. I think Dropbox has that kind of feature to look on the SD card. If set on a weekly basis, the worst that can happen is 6 days of data being lost.

[raydude]

Right now she won't use her tablet and is asking me to make backups of her laptop...

She'll let it go eventually. I'm thinking about formatting it as a data card to make sure the data will be readable in most cases.