How to mount this (exFAT) sd card that isn't getting recognized?

veeruk101 · 12-06-2012, 10:05 AM

I have a new 64GB Sandisk sd card that I put into my mobile phone (Android) and after a few weeks of use it stopped recognizing the card. How can I manage to mount it on my Linux computer? I put it into the computer and got the following information:

Code:

$ sudo fdisk -l /dev/mmcblk0

Disk /dev/mmcblk0: 63.9 GB, 63864569856 bytes
255 heads, 63 sectors/track, 7764 cylinders, total 124735488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

        Device Boot      Start         End      Blocks   Id  System
/dev/mmcblk0p1           32768   124735487    62351360    7  HPFS/NTFS/exFAT

As well as the following:

Code:

$ sudo fdisk -l /dev/mmcblk0p1

Disk /dev/mmcblk0p1: 63.8 GB, 63847792640 bytes
4 heads, 16 sectors/track, 1948480 cylinders, total 124702720 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xf4f4f4f4

This doesn't look like a partition table
Probably you selected the wrong device.

          Device Boot      Start         End      Blocks   Id  System
/dev/mmcblk0p1p1   ?  4109694196  8219388391  2054847098   f4  SpeedStor
/dev/mmcblk0p1p2   ?  4109694196  8219388391  2054847098   f4  SpeedStor
/dev/mmcblk0p1p3   ?  4109656385  8219350580  2054847098   f4  SpeedStor
/dev/mmcblk0p1p4   ?  4109694196  4109756903       31354   f4  SpeedStor

Partition table entries are not in disk order

In order to try to mount it I do the following but get error messages. Any idea how I could solve this to mount it successfully?

Code:

$ sudo apt-add-repository ppa:relan/exfat
$ sudo apt-get update
$ sudo apt-get install fuse-exfat
$ sudo mount -t exfat /dev/mmcblk0 /mnt/sdcard
FUSE exfat 0.9.8
ERROR: exFAT file system is not found.
$ sudo mount -t exfat /dev/mmcblk0p1 /mnt/sdcard
FUSE exfat 0.9.8
ERROR: exFAT file system is not found.

michaelk · 12-06-2012, 10:41 AM

You did not specify the partition ID.

Quote:

sudo mount -t exfat /dev/mmcblk0p1 /mnt/sdcard

The partition table only resides in the MBR which is why you get an error with
fdisk -l /dev/mmcblk0p1

P.S. I missed the second mount command where you did specify the partition ID. Lets see if it is really an exfat filesystem
Try:
file -s /dev/mmcblk0p1

veeruk101 · 12-06-2012, 10:44 AM

It's the same problem with both versions of the command:

Code:

$ sudo mount -t exfat /dev/mmcblk0 /mnt/sdcard
FUSE exfat 0.9.8
ERROR: exFAT file system is not found.

Code:

$ sudo mount -t exfat /dev/mmcblk0p1 /mnt/sdcard
FUSE exfat 0.9.8
ERROR: exFAT file system is not found.

michaelk · 12-06-2012, 10:55 AM

The output of the file command will tell us if the SD card is actually formated as exfat. The card could of just failed which means it can not be read anymore.

veeruk101 · 12-06-2012, 11:01 AM

Here is the output:

Code:

$ sudo file -s /dev/mmcblk0
/dev/mmcblk0: x86 boot sector; partition 1: ID=0x7, starthead 10, startsector 32768, 124702720 sectors, extended partition table (last)\011, code offset 0x0

Code:

$ sudo file -s /dev/mmcblk0p1
/dev/mmcblk0p1: x86 boot sector, code offset 0x52

The data can actually be read in some recovery systems of my Android device so the card is still is working order. I feel like while I was doing some modifications to my (rooted) phone something might have changed partiiton tables or something like that.

michaelk · 12-06-2012, 11:54 AM

Not much help there.

lleb · 12-06-2012, 02:16 PM

this link might help:

http://www.transformerforums.com/for...rosd-woes.html

veeruk101 · 12-06-2012, 06:10 PM

I tried to mount it as NTFS but still get an error:

Code:

$ sudo mount -t ntfs /dev/mmcblk0p1 /mnt/sdcard
NTFS signature is missing.
Failed to mount '/dev/mmcblk0p1': Invalid argument
The device '/dev/mmcblk0p1' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

Any idea how I can mount this drive?

jefro · 12-06-2012, 07:37 PM

I think the issue is, "it did work". Makes me think there is damage.

respawnd · 12-07-2012, 02:24 AM

I am assuming you have something of value on the SD card that you are trying to preserve. If I were you I would dump the image to disk then mount the image and make sure your data is there. If you cannot even dump the image then the card is bad. Use something like

Code:

dd if=/dev/mmcblk0p1 of=badcard.img bs=4M #or whatever bs you think works

.
Then mount the image using the Disk Manager or mount (as a loopback file system). You should be able to run

Code:

fdisk -l /path/to/badcard.img

and get the same result as before. I would then try mounting the image with different type options. You can make as many copies of badcard.img as you like and be as destructive as necessary to get the right type.

I am surprised to read that you are using exFAT. Unless you have very new drivers on your rooted Android, I would not have expected exFAT to work.

veeruk101 · 12-07-2012, 02:36 AM

Dumping the file as you suggested works fine, thanks for the suggestion, and I can even restore all the files (something like 90,000 of them) using recovery software 'photorec'. The reason why I'd like to mount the filesystem is that I can get back the files with the appropriate timestamps, filenames, and just for the files I need. Maybe 1,000 files are the ones that are actually mine, rather than belonging to other Android apps and other things stored on the sd card - I'd have to dig through 90,000 recovered files to find the ones I need if I stop here.

(On my rooted Android I am using the latest versions of some custom ROMs, so maybe that's why exFAT worked on it.)