ERROR: exFAT file system is not found

[Vincenzo Li Vigni]

Hi all,

I have compiled the svn version of fuse-exfat on a PowerPC G4 with Mac OS 10.5 (Leopard). The only fix I used was to change this line on SConstruct:

#env = Environment(**ARGUMENTS)

env = Environment(CPPPATH = ['include','/usr/local/include/osxfuse/'])

I can mount properly a disk formatted as exfat on Mac OS Lion but I can't mount another one I created on Windows 7. Both partitions are recognized as exfat by Windows 7, where I can see all the files without problems.

Now some terminal grabs:

1) mount attempt on the "problematic" disk: 

$ sudo mount.exfat /dev/disk2s3 /Volumes/Sam_exFAT/

FUSE exfat 0.9.7

ERROR: exFAT file system is not found.

2) fdisk on the "problematic" disk 

$ fdisk /dev/disk2

Disk: /dev/disk2 geometry: 19456/255/63 [312571224 sectors]

Sector size: 1024 bytes

Signature: 0xAA55

         Starting       Ending

 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]

------------------------------------------------------------------------

 1: EE 1023 254  63 - 1023 254  63 [         1 -     204819] <Unknown ID>

 2: AF 1023 254  63 - 1023 254  63 [    204820 -   57671680] HFS         

 3: 07 1023 254  63 - 1023 254  63 [  57876500 -  254684140] HPFS/QNX/AUX

 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused   

3) mount on the "working" drive:

$ sudo mount.exfat /dev/disk3s2 /Volumes/WD_exFAT/

FUSE exfat 0.9.7

4) ls on the mounted "working" drive

ls -l /Volumes/WD_exFAT/SCAN0001.PDF 

-rwxr-xr-x  1 root  wheel  581814 Apr 24 12:05 /Volumes/WD_exFAT/SCAN0001.PDF

5) fdisk on the "working" drive:

$ fdisk /dev/disk3Disk: /dev/disk3 geometry: 121597/255/63 [1953458176 sectors]

Signature: 0xAA55

         Starting       Ending

 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]

------------------------------------------------------------------------

 1: AF 1023 254  63 - 1023 254  63 [         2 -  976991232] HFS+        

 2: 07 1023 254  63 - 1023 254  63 [ 976991235 -  976466941] HPFS/QNX/AUX

 3: 00    0   0   0 -    0   0   0 [         0 -          0] unused      

 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused    

[Andrew Nayenko]

Hi Vincenzo,

The "problematic" disk looks very interesting: fdisk says it uses 1KB
sectors. This can be the reason of fuse-exfat failure. What kind of
device is it (vendor, model)?

Unfortunately I cannot say anything without having the raw data. If you
don't mind wiping out the "problematic" volume:
1) erase the volume with
sudo dd if=/dev/zero of=/dev/disk2s3 bs=1m
2) format it to exFAT in Windows
3) make sure that fuse-exfat fails to mount it
4) create a compressed dump with
sudo gzip -c /dev/disk2s3 > disk2s3.dump.gz
5) send me the dump (it should be rather small).
Having a complete dump of an FS would help a lot because I'll be able to
do any testing myself.

If you cannot erase the volume, just send me the compressed dump of it's
first megabyte:
sudo dd if=/dev/disk2s3 of=disk2s3.dump1mb bs=1m count=1
gzip disk2s3.dump1mb

--
Andrew Nayenko <res...@gmail.com>

[volt...@voltagex.org]

Hi Andrew and Vincenzo.

I am having the same problem - "exFAT file system is not found"

The partition table looks like:

Disk /dev/sdc: 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/sdc1           32768   124735487    62351360    7  HPFS/NTFS/exFAT

This SDXC card was formatted with a Galaxy S3 that is currently broken, and I'd like to get the files off for now.

I'm dumping the filesystem now but as it's 64GB it's going to take some time

[volt...@voltagex.org]

I tried to attach a 1mb section from the start of the partition, but Google wouldn't let me post it. It's at http://ge.tt/3gSy9OU/v/0

[Andrew Nayenko]

Hi,

The superblock is corrupted, including signature bytes (that's why
fuse-exfat says there is no exFAT). Try to restore it from the copy (in
exFAT 12th sector contains a backup copy of the 1st):

dd if=sdc1.onemb of=sdc1.onemb bs=512 count=1 conv=notrunc skip=12

> I tried to attach a 1mb section from the start of the partition, but Google
> wouldn't let me post it. It's at http://ge.tt/3gSy9OU/v/0

--
Andrew Nayenko <res...@gmail.com>

[Adam Baxter]

will exfat be able to mount the 1mb file so I can try this on the smaller file first?

[Andrew Nayenko]

> will exfat be able to mount the 1mb file so I can try this on the smaller
> file first?

No, try 100MB at least. Also use "-o ro" to make fuse-exfat work with
the image in read-only mode so that it does not make things worse if
something goes wrong.

> On 29 December 2012 18:45, Andrew Nayenko <res...@gmail.com> wrote:
>
>> Hi,
>>
>> The superblock is corrupted, including signature bytes (that's why
>> fuse-exfat says there is no exFAT). Try to restore it from the copy (in
>> exFAT 12th sector contains a backup copy of the 1st):
>>
>> dd if=sdc1.onemb of=sdc1.onemb bs=512 count=1 conv=notrunc skip=12
>>
>>
>> I tried to attach a 1mb section from the start of the partition, but
>>> Google
>>> wouldn't let me post it. It's at http://ge.tt/3gSy9OU/v/0
>>>
>>
>> --
>> Andrew Nayenko <res...@gmail.com>
>>
>

--
Andrew Nayenko <res...@gmail.com>

[Adam Baxter]

FUSE exfat 0.9.7
fuse: mount failed: Block device required

[Andrew Nayenko]

sudo mount -o loop -t exfat your_image_file /mnt/your_mount_point

--
Andrew Nayenko <res...@gmail.com>

[Adam Baxter]

That completes, printing out the exfat version number, but when I try to ls, I get

ls: cannot open directory .: Transport endpoint is not connected

[Adam Baxter]

Oops, replying on-list this time.

Latest from SVN gives slightly more information -
root@osiris:/media/voltagex/

Data# sudo mount -o loop -t exfat exfat.img ../testone/
FUSE exfat 0.9.8
WARN: volume was not unmounted cleanly.
root@osiris:/media/voltagex/Data# cd ../testone
root@osiris:/media/voltagex/testone# ls

[Andrew Nayenko]

Was exfat.img incomplete dump of the FS? If so, it's OK: superblock checks passed. Try to repair and mount the complete dump. Again, I'd recommend to use "-o ro".

[volt...@voltagex.org]

No good, even with a complete copy of the drive.

[volt...@voltagex.org]

It lives!

After fiddling with buffered writes for a minute the card is now reading fine.

Can I donate to your project or to a charity of your choice?

Thanks
Adam

[Andrew Nayenko]

> It lives!
>
> After fiddling with buffered writes for a minute the card is now reading
> fine.

Fine!

> Can I donate to your project or to a charity of your choice?

Please donate to FSF (https://my.fsf.org/donate). Thanks!

--
Andrew Nayenko <res...@gmail.com>

[ialex...@gmail.com]

Hi everyone,

I'm having some issues with being unable to mount an exFAT filesystem and I keep getting the same error described above.  ("ERROR: exFAT file system is not found.")

My system is Ubuntu 12.10 and exfat FUSE 1.0.1

I have a Seagate portable hard drive that was dropped and stopped working.  I believe the partition table on the disk was intact, and my issues come from somewhere within the exFAT partition.

After a long time spent with GNU ddrescue running on it, I've recovered all but 5MB of the data on that drive.  I called the image file that process produced ddrescue1.copy.img

I believe this file, the ddrescue log, specifies where those 5MB worth of holes in my image are.  http://ge.tt/4VwGgVX/v/0?c)

This command should mount the image:
    sudo mount -t exfat -o loop,ro,noexec ~/emergencymove/ddrescue1.copy.img /media/mtpt1
But all it returned is:
    FUSE exfat 1.0.0

    ERROR: exFAT file system is not found.

But wait - I literally just ran that same command again right now and got this:
    FUSE exfat 1.0.1
    ERROR: invalid VBR checksum 0xeed9cbd (expected 0x9a40a92a).

So now I just ran this command:
    sudo dd if=ddrescue1.copy.img of=ddrescue1.copy.img.onemb bs=1M count=1
And here's the output:
    http://ge.tt/2XQGiVX/v/0?c

Would you mind taking a look and telling me what you think?  Thanks for this amazing (and amazingly useful) tool!
Alex

[Andrew Nayenko]

Hi Alex,

Try the attached patch. It makes "invalid VBR checksum" error non-fatal.
If you are lucky enough your image will be mounted.

--
Andrew Nayenko <res...@gmail.com>

[ialex...@gmail.com]

Wow - thank you so much! I have to admit that I don't know quite what to do with the patch file...

Some reading tells me I have to run patch -p0 < nonfatal.....

But that seems to require I know where libexfat is.  Is there a standard place to find that?

Here's hoping this works!

Alex

[Andrew Nayenko]

This article explains how to compile fuse-exfat:
http://code.google.com/p/exfat/wiki/HOWTO

Get the source:
svn co http://exfat.googlecode.com/svn/trunk/ exfat-read-only
Change directory:
cd exfat-read-only
Apply the patch:
patch -p0 < nonfatal-invalid-vbr.patch
Build and install:
scons
sudo scons install

>> Andrew Nayenko <res...@gmail.com <javascript:>>
>>
>

--
Andrew Nayenko <res...@gmail.com>

[ialex...@gmail.com]

Thank you very much for the detailed tutorial, sorry for my ignorance.  The patch seemed to work, and exited successfully.

Unfortunately, though, the image still didn't mount.  When I ran the same command as always:

sudo mount -t exfat -o loop,ro,noexec ~/emergencymove/ddrescue1.copy.img /media/mtpt1

I got this:

FUSE exfat 1.0.0

ERROR: invalid VBR checksum 0xeed9cbd (expected 0x9a40a92a).

ERROR: upcase table is not found.

Any suggestions at this point?  Here is the first 50MB of the image, if that helps: https://mega.co.nz/#!QVZ2CRSJ!IOEoOWPkW-fqOqVeyXTZ3Ec6GI5vUSinl4KaDL8rDFY

Thank you so much for making this amazing tool, and for your unbelievably fast response time and helpful attitude! I really hope this works...

Alex

[Andrew Nayenko]

Bad news. Root directory is all zeros.

I had a look at your dump using hexdump. Most of it is filled with a
strange counter, like this:

004ad8c0 000eb631 000eb632 000eb633 000eb634 |1...2...3...4...|
004ad8d0 000eb635 000eb636 000eb637 000eb638 |5...6...7...8...|
004ad8e0 000eb639 000eb63a 000eb63b 000eb63c |9...:...;...<...|
004ad8f0 000eb63d 000eb63e 000eb63f 000eb640 |=...>...?...@...|
004ad900 000eb641 000eb642 000eb643 000eb644 |A...B...C...D...|
004ad910 000eb645 000eb646 000eb647 000eb648 |E...F...G...H...|
004ad920 000eb649 000eb64a 000eb64b 000eb64c |I...J...K...L...|
004ad930 000eb64d 000eb64e 000eb64f 000eb650 |M...N...O...P...|
004ad940 000eb651 000eb652 000eb653 000eb654 |Q...R...S...T...|
004ad950 000eb655 000eb656 000eb657 000eb658 |U...V...W...X...|

Looks like your disk reads nonsense.

[ialex...@gmail.com]

Bummer! But I'm glad to know that I can stop barking up this particular tree. One last quick question before I quit bothering you - would it be valuable to either go after it with PhotoRec or with professional data recovery software or with a professional data recovery service?

Thanks!
Alex

[Andrew Nayenko]

> Bummer! But I'm glad to know that I can stop barking up this particular tree. One last quick question before I quit bothering you - would it be valuable to either go after it with PhotoRec or with professional data recovery software or with a professional data recovery service?

I don't know, I have no experience in data recovering. I prefer regular backups.

> Thanks!
> Alex
>
> --
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