MultiDrive – free backup, clone & wipe disk utility from Atola Technology

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: exFAT VBR broken
PostPosted: June 27th, 2014, 17:27 
Offline

Joined: June 27th, 2014, 17:23
Posts: 2
Location: Belgium
Hi there,

One of my external HD's is formatted to exFAT (it's a WD, 2.5'' 1 TB) because I move files around a lot between Ubuntu, Mac and Windows. It seemed a good choice at the time.

However, apparently Macs 'eat' exFAT bootsectors for breakfast and this recently also happened to mine. By using CGSecurity's fantastic tool Testdisk (http://www.cgsecurity.org/wiki/TestDisk) I was able to find out that the Volume Boot Record has been overwritten with zeroes :? As always, the files on this HD are important and I have been too lazy to backup everything :(

Question: Is there a tool (for linux) that can repair exFAT VBR's ? I could obviously download and install the similar fsck_exfat on a Mac, but I was wondering if Ubuntu could fix this for me. I just happen to like Linux better

Thanks, esteemed panel :)


Top
 Profile  
 
 Post subject: Re: exFAT VBR broken
PostPosted: June 27th, 2014, 21:01 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 16960
Location: Australia
AFAICT, sectors 0 - 11 constitute the Primary VBR while sectors 12 - 23 are the Backup VBR. I have no experience with exFAT, but perhaps the solution may be as simple as using a disc editor to copy the backup sector(s) over the primary ones. Perhaps TestDisk can do this? BTW, it would be advisable to clone your drive first.

Here is one document I found useful:
http://www.sans.org/reading-room/whitep ... stem-33274

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: exFAT VBR broken
PostPosted: June 27th, 2014, 22:52 
Offline
User avatar

Joined: December 4th, 2012, 1:35
Posts: 3903
Location: Adelaide, Australia
That's a good article, I read it.. well as much as I could, last year. I advise also to checkout the references at the end of the doc and get even more great papers. In fact I do this on most things I read.

Thanks Franc


Top
 Profile  
 
 Post subject: [SOLVED] Re: exFAT VBR broken
PostPosted: June 28th, 2014, 5:39 
Offline

Joined: June 27th, 2014, 17:23
Posts: 2
Location: Belgium
Thanks fzabkar for your reply ! Truly appreciated :D

I did as you were told: copied backup over main superblock. Still couldn't acces the drive :( (not in Linux, nor Mac, nor Win)

I let TestDisk run it again and all of a sudden I could acces the filelist again. I'm now copying everything over to a different external HD and will format this WD afterwards. To another filesystem. No more exFAT for me as long as I have to use Mac... :twisted:

Thanks again !! :good: :good:

[SOLVED]


Top
 Profile  
 
 Post subject: Re: exFAT VBR broken
PostPosted: June 22nd, 2016, 11:33 
Offline

Joined: June 22nd, 2016, 11:26
Posts: 1
Location: La Jolla, CA
Sorry to dig out this old thread. I have a situation similar to this.
I have an external storage with 2 x 2TB ( Stardom 2Bay, JBOD mode ) that was working nicely with my Macmini .

Somehow since last week the disk is not readable anymore. I got the message that " The disk you inserted was not readable by this computer " and it asked to "Initialize", "Ignore" or "" Eject".

OS is the newest El Capitan (10.11.5) and I've tried other enclosure and docking station and all saw the same message.

I also tried multiple computers (MBAs, MB, PC Win 7) and got the same issue.

I then started trying to repair it on OSX Terminal: "diskutil list" showed me the disk is now disk3 without partition.

So I did this first: sudo diskutil verifyVolume /dev/disk3 and I got the error message: " Error starting file system verification for disk3: Unrecognized file system (-69846)" .

Then I used "sudo fsck_exfat -d /dev/disk3".

Now I got the message:

"Opening /dev/rdisk3 ** 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."

I then looked into TestDisk in Linux.

http://imgur.com/a/HoWrJ
The picture was taken around 15% but I did complete the analysis.
But it seems like not recoverable.

I am trying to scan it with R-studio for data recovery now and found that the label is 00000000000000000000. The scan is still ongoing since it is doing slowly. But I think this might be related to your post regarding the broken VBR. However I don't understand how you exactly fixed the VBR.

Thanks for your suggestions.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 124 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group