Wednesday, May 20, 2015

Unable to mount ExFat external HDD (' stderr:' has invalid checksum)

Hi All,

I have an external hard drive(Western Digital My Passport Ultra 1TB) which I keep all my movies, work stuff and etc. Initially I formatted the drive in ExFat format in Mac OS X platform so that I can use it in Windows and Mac. Also Ubuntu seems to have a fix to read ExFat file systems[1].

But recently when I connected this external hard drive to my Ubuntu machine, it gave me this error(something similar) saying that it cannot mount the disk: 
Error mounting /dev/sdb1 at /media/rbuse/My Passport: Command-linemount -t "exfat" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,io charset=utf8,namecase=0,e rrors=remount-ro,umask=0077" "/dev/sdb1" "/media/rbuse/My Passport"' exited with non-zero exit status 1: stdout:FUSE exfat 1.0.1

stderr:' has invalid checksum (0x6634 != 0x4044). '
I was stunned because all my work was in there, especially my VDIs. 

So I started my research and one solution was to plug it back in to my Mac OS X machine and use the "Disk Utility" tool to repair it(Use "Repair Disk" button) [2][3]. When I tried this, the following error came up.
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.
I was like "Huh?!?!?" . I continued my research and found that if I attempt several times to "Repair Disk", it will work at sometime[4]. I tried like 20+ times, it didn't work.

So I googled more and found a command that should fix the broken external hard drive [5][6][7].
sudo fsck_exfat -d <device>
To find the correct value for <device>(eg : disk1s2) use the following command[8] to list down the device IDs.
diskutil list
At the end of the fsck_exfat command, I got the following error[9]. 
fsck_exfat: Could not update main boot region: Bad file descriptor

As the last attempt to fix, I used the "chkdsk" command of Windows OS[10]. And IT WORKED!!. I ran the following command. It took sometime to complete the task. So be patient.
chkdsk /f <Volume_ID>
Here the Volume_ID refers "C:" or "D:" of the corrupted hard disk. eg : 
chkdsk /f D:

Hope this article helped!,


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1 comment:

  1. I had the exact same problem with the exact same hardware and my problem was solved with the command :
    sudo fsck_exfat -d
    Just be sure to unmount the relative before running the former command, with :
    diskutil unmountDisk /dev/[your disk]