exFAT volume often gets corrupted

Please Help,

I have read this entire thread, however, my difference is I do not have a s# when I type "diskutil list". My drive only shows as "disk2". The following is a cut and paste of what I see in terminal. I have run a full scan of the drive with R-studio and it shows that the partition is intact, however, neither windows nor OS X will mount it.

Last login: Tue Jul 14 15:40:04 on console

Jacksons-MacBook-Air:~ Jacksons_MacBookAir$ diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.3 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_CoreStorage 499.4 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS Macintosh HD *499.0 GB disk1

Logical Volume on disk0s2

11616BA5-2978-4F7D-A440-F91A2758EE65

Unencrypted

/dev/disk2

#: TYPE NAME SIZE IDENTIFIER

0: *3.0 TB disk2

Jacksons-MacBook-Air:~ Jacksons_MacBookAir$ sudo fsck_exfat -d disk2

Password:

Opening /dev/rdisk2

** Checking volume.

** Checking main boot region.

fsck_exfat: Invalid jump or signature

Main boot region is invalid. Trying alternate boot region.

** Checking alternate boot region.

fsck_exfat: Invalid jump or signature

Alternate boot region is invalid.

** The volume could not be verified completely.

Thank you in advance,

Jack

The fsck_exfat method you proposed worked for me, too - THANK YOU!!! Strikes me as a very serious shortcoming that Mac OS X 10.8.4 managed to corrupt an exFAT partition that I had only created because it was proposed by Disk Utility (good idea for Windows interchange, no?), and that had only ever been touched by Mac OS X, and only for a couple hours, writing some large 10 GB video files, around 300 GB all in all. Good I got them back!

Had some issues with corrupted exFAT partition that Disk Utility said it couldn't repair.

2012-09-06 21:35:31 +0200: Verify and Repair volume “disk0s4”

2012-09-06 21:35:31 +0200: Starting repair tool:

2012-09-06 21:35:31 +0200: Checking file system2012-09-06 21:35:31 +0200: ** /dev/disk0s4

2012-09-06 21:35:31 +0200: Invalid sector size: 0

2012-09-06 21:35:31 +0200: Volume repair complete.2012-09-06 21:35:31 +0200: Updating boot support partitions for the volume as required.2012-09-06 21:35:31 +0200: Error: Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files.2012-09-06 21:35:31 +0200:

2012-09-06 21:35:31 +0200: Disk Utility stopped repairing “disk0s4”: Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files.

2012-09-06 21:35:31 +0200:

Looked like crazy on the net for solutions but couldn't find any. I started to poke around in the terminal and ran this:

fsck_exfat -d disk0s4

The -d flag is the debug flag and it gave me hope. I saw all my files flashing by and after a while I got this question:

Main boot region needs to be updated. Yes/No?

I hesitated for a long while but realized that I didn't have any other option. I picked yes and it said that it repaired the drive. It didn't appear on the desktop though. I ran fsck_exfat again and now it said that the disk was ok. I fired up Disk utility and tried to repair the drive there once again and now disk utility could repair it! =)))

Just wanted to share this lil advice since it seems common that exfat partions gets corrupted in OSX. I'm running 10.8.1 on rMBP here. I have no idea why Disk Utility doesn't call fsck and instead says that the disk can't be repaired. The tools for repairing it is in the OS and apparently and obviosusly it was fixable (...in my case).

Cheers

Yes. disk0s4 was the partition in my case, but there's nothing sayting that it's that in your setup. You could start with running this in the terminal.

diskutil list

In my setup that gives me

So in the output at your place you have to find the 'name' of your partition and look to the right in the 'identifier' column and use that partition identifier in the command. In your last example you just use 'disk2' which isn't a partition identifier but the disk itself.

Hope this helps.

Cheers

Hi, I also have an Exfat drive that went corrupted, I checked all different kinds of solutions , especially the one from neo_amiga who looked very promising, unfortunately for me the things went a bit differently.

Here's a screenshot of my disk info from the Disk Utility, i hope it helps (sorry for the french i'm sure you can compare with your own disk to understand the table better 🙂) it stills says the disk is fixable

if i got this right, the index isnt just corrupted but completely missing.. if some has an idea of what to do 🙂

Could be the exFAT implementation that Mac OS X uses to format the drive. Everytime I tried to use that format, formatted on a Mac, no Windows computer could read that drive. When formatted exFAT on a windows PC both Mac and Windows could read and writer to it.

I suggest you dump the exFAT partition, esoecially it is using the GUID partition table.

When I briefly had a Boot Camp partition and Win 7 installed on my MBP I could read and write to the Mac partition from Windows and could read and write to the Win partition from the Mac side. At least I think I could. Now that may be something that was included in Boot Camp V4 and you may be running an older version of BC. Not sure.

32 GB thumbdrive, formatted as exFAT by Windows. That drive is dedicated to only shared data so should not be corrupted by the partition-mapping.

And very portable, although slow-ish.

Bus-powered USB drive also possible -- light and small. Bus-powered is bad for backups but seems OK for data-share.

Ok sorry I remembered wrong then. No need to have Windows in it own partition on my Mac. I have windows PCs for that.

zdenekfromnew york wrote:

I got latest of version of BC and cannot write to HFS+ (Mac) drives, read only.

exFAT, well I got it formatted by Mac probably. Ill try format it by Windows then and I'll see how that goes but I dont think there will be any difference.

NEO_AMiGA you just spared me a whole lot of grief!

I didn't realize that exfat drives corrupt easily and that there was a simple tool to fix it (fsck_exfat). I thought I had more serious issues with my partition table so tried to rebuild it using testdisk. Unfortunately i must have screwed up the hybrid mbr since bootcamp is now not bootable. One problem at a time...

NEO_AMiGA You are my savor!!!!!!!!! Thank you so much I have spent hours trying to resolve this issue over the past year. I origionally discovered that Dawesi was right and chkdsk can fix it most of the time however windows needs to be able to recognise the partion as exfat, if not this option wont work. I spent five hours today trying to figure out how to change my partition back to exfat from ntfs (it is not and never has been). Your solution should be looked at by apple and incorperated into the new disk utility or at least posted somewhere proment on the forum. APPLE pay attention feature this thread!!!!

Hi !

thanks you for NEO_AMIGA for this post

it's also the 2nd time for the last 3 month that my exFat gets corrupted after booting OsX.. on the first time I suspected the disk (samsung) and changed it to a WD.. but this morning I encoutered again this error from diskutils.

invalid sector size: 0

the tool I found that could recover every files properly was R-Studio 6.1 for windows, (whereas GetDataback and all that good stuff from Hiren's didn't helped this time).

now I don't need it, thanks to the fsck-exfat command.

Does someone have an idea on how avoid these exFat corruptions ? do you think it can be caused by Paragon NTFS for mac ? (well, it shouldn't, while it's exFat..)

NEO_AMiGA, I'm going to echo what everyone else has said.

THANK YOU THANK YOU THANK YOU!

You saved me a LOT of drive juggling to try to save my data.

(Now, I'm off to the store for a 1-2TB USB drive for secondary drive backups)

NEO-AMIGA, Thank-you, Thank-you, Thank-you. That is now my goto FAST-FIX. This happened before & took me hours to work out reading thru Terminal Syntax, then I wrote down how I fixed it in case it happened again & lost it! But it wasn't as simple as your post. Thanks Again!