Here is my situation :
I have an external hard drive of 320Gb.
The drive is plugged using a disk docking, and mounts automatically when started.
I can explore the directory tree, read and write in the mounted partition.

The mounted partition seems to be FAT32 ("seems" cause I can't find the information).

My goal is to erase the disk, and create a new exFat partition. I did not succeed to achieve this.
I tried formating the disk with gnome-disks : Error synchronizing after initial wipe: Timed out waiting for object (udisks-error-​quark, 0)
I tried gparted and on startup it says end of file while reading /dev/sdb” and then show that the disk is unallocated of size 512B.

Note that I immediately made a backup.
I also tried to connect the disk using different dockings.

I read many threads about hard drive problematics, but didn't find one where someone is the same situation, so before starting messing up I'd like to get some advices as I am definitely not skilled there.

Here is some informations :

What dmesg gives me when I plug the disk :

$ sudo dmesg
[72866.922181] usb 1-2: new high-speed USB device number 39 using xhci_hcd
[72867.074593] usb 1-2: New USB device found, idVendor=059f, idProduct=0828, bcdDevice= 0.00
[72867.074601] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[72867.074605] usb 1-2: Product: d2 Quadra
[72867.074609] usb 1-2: Manufacturer: LaCie   
[72867.074613] usb 1-2: SerialNumber: 00D04B7A10097C8E
[72867.082929] usb-storage 1-2:1.0: USB Mass Storage device detected
[72867.084025] scsi host2: usb-storage 1-2:1.0
[72867.086319] input: LaCie    d2 Quadra as /devices/pci0000:00/0000:00:15.0/usb1/1-2/1-2:1.1/0003:059F:0828.0008/input/input25
[72867.147133] hid-generic 0003:059F:0828.0008: input,hidraw1: USB HID v1.11 Device [LaCie    d2 Quadra] on usb-0000:00:15.0-2/input1
[72868.096079] scsi 2:0:0:0: Direct-Access     ST332082 0AS              3.AA PQ: 0 ANSI: 4
[72868.099156] sd 2:0:0:0: Attached scsi generic sg1 type 0
[72868.101805] sd 2:0:0:0: [sdb] 625142448 512-byte logical blocks: (320 GB/298 GiB)
[72868.102191] sd 2:0:0:0: [sdb] Write Protect is off
[72868.102193] sd 2:0:0:0: [sdb] Mode Sense: 10 00 00 00
[72868.104502] sd 2:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[72868.121742]  sdb: sdb1
[72868.123517] sd 2:0:0:0: [sdb] Attached SCSI disk

The partition is mounted at /media/user/BACKUP :

$ lsblk
sda            8:0    0 111,8G  0 disk 
└─sda1         8:1    0 111,8G  0 part /home
sdb            8:16   0 298,1G  0 disk 
└─sdb1         8:17   0 298,1G  0 part /media/user/BACKUP
mmcblk0      179:0    0  29,1G  0 disk 
├─mmcblk0p1  179:1    0   512M  0 part /boot/efi
├─mmcblk0p2  179:2    0  27,7G  0 part /
└─mmcblk0p3  179:3    0   976M  0 part [SWAP]
mmcblk0boot0 179:256  0     4M  1 disk 
mmcblk0boot1 179:512  0     4M  1 disk 

This is telling me that the partition is FAT32 :

$ cp ~/movies/BigMovie.mkv /media/user/BACKUP/BigMovie.mkv 
cp: error writin '/media/user/BACKUP/BigMovie.mkv': File too large

ls -l /media/user/BACKUP/ 
total 4194368
-rw-r--r--  1 user user 4294967295 juin  29 10:51 BigMovie.mkv

The (non-existent) partition table on parted (or using fdisk) :

$ sudo parted /dev/sdb
GNU Parted 3.2
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Model:  (file)
Disk /dev/sdb: 512B
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start  End  Size  Type  File system  Flags


$ sudo fdisk /dev/sdb
Commande (m pour l'aide) : p
Disque /dev/sdb : 512 B, 512 octets, 1 secteurs
Unités : secteur de 1 × 512 = 512 octets
Taille de secteur (logique / physique) : 512 octets / 512 octets
taille d'E/S (minimale / optimale) : 512 octets / 512 octets
Type d'étiquette de disque : dos
Identifiant de disque : 0xfd445558

I've tried anyway to alterate the partition scheme with fdisk :

$ sudo fdisk /dev/sdb
# trying a dos partition table
Command (m for help): o
Created a new DOS disklabel with disk identifier 0x98d9e56d.

# at this point it seems alreayd lost
Command (m for help): n
All space for primary partitions is in use.

Command (m for help): w
The partition table has been altered.
Syncing disks.

# nothing changed
Command (m for help): p
Disk /dev/sdb: 512 B, 512 bytes, 1 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
Disklabel type: dos
Disk identifier: 0x98d9e56d

# trying GPT
Command (m for help): g
Created a new GPT disklabel (GUID: 9E30965C-889B-A249-B6D7-71580BCE1CBE).

Command (m for help): n
Partition number (1-128, default 1): 
First sector (34-18446744073709551583, default 34): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (34-18446744073709551583, default 18446744073709551583): 

# 16 EiB ? I'd like too !
Created a new partition 1 of type 'Linux filesystem' and of size 16 EiB.

# as expected
Command (m for help): w
fdisk: failed to write disklabel: Invalid argument

Thanks for your help !

  • is there some data on disk you need to save or you just want to erase everything and create new partition?
    – Shah Fahad
    Jun 29, 2021 at 10:53
  • Everything is backed up, so erasing all is ok.
    – T3e
    Jun 29, 2021 at 11:06
  • I think the problem is with your partition table but just to be sure check with another tool fdisk. Run sudo fdisk /dev/sdb and in interactive mode use the p command.
    – Shah Fahad
    Jun 29, 2021 at 11:09
  • I edited my message with the results of sudo fdisk /dev/sdb, but I don't find it more relevant.
    – T3e
    Jun 29, 2021 at 11:23

2 Answers 2


You can use fdisk. Assuming you disk is /dev/sdb, run sudo fdisk /dev/sdb and in interactive mode use the option g to create a gpt partition table or o to create a dos partition table. After that create a new partition using the command n, by default it creates a partition with partition type Linux Filesystem, you can change that using the t option and then selecting Microsoft basic data as the partition type, then use the p option to see the final partition layout, then use the w option to write changes to the disk. Now after that you can use the command sudo mkfs.exfat /dev/sdb1 to format the partition as exfat. Finally you can once again use the command sudo fdisk /dev/sdb and then p option to make sure everything is correct and after that you can mount the partition wherever you want.

  • I edited my message with the results of the fdisk procedure. It looks like fdisk is lost with that disk.
    – T3e
    Jun 29, 2021 at 11:51
  • Try to zero out the first sector of disk, use dd if=/dev/null of=/dev/sdb bs=512 count=1 and then move forward and see what happens. Make sure disk is unmounted
    – Shah Fahad
    Jun 29, 2021 at 11:57

I followed Shah Fahad instructions and after running dd if=/dev/null of=/dev/sdb bs=512 count=1, I tried again to format the drive :

$ sudo fdisk /dev/sdb
fdisk: unable to open /dev/sdb: No such file or directory

Google guided me to this guided me to this answer : https://unix.stackexchange.com/a/56519/267558 and reboot fixed my problem.

So it looks like that trying to get things up, I had unfortunately unmounted /dev/sdb ...

I hope dd didn't broke anything.

  • why would dd break anything? It was removing the partition table on your disk. In the comment above i meant to say: make sure partition is unmounted
    – Shah Fahad
    Jun 29, 2021 at 12:46
  • The partition was unmounted. I don't really know how dd works, for me it looks like that I have written data on /dev/sdb while /dev/sdb was not pointing to the drive. So where did the data was written ? Hope nowhere important. That is my worry.
    – T3e
    Jun 29, 2021 at 13:07
  • dd does not need a partition to be mounted to write to it. It works at block level. It is highly likely that the data was written to your drive i.e /dev/sdb because dd would have thrown an error if it was not able to write. Also by doing this your dos partition table was cleared, which was creating problem while creating new partition table. Thus when you rebooted you got a completely erased disk.
    – Shah Fahad
    Jun 29, 2021 at 13:44

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