USB Stick corrupted - The driver descriptor says the physical block size is 2048 bytes

Bug #1708881 reported by Damiön la Bagh on 2017-08-05
This bug affects 5 people
Affects Status Importance Assigned to Milestone
usb-creator (Ubuntu)

Bug Description

After using the usb-creator-gtk program the resulting Ubuntu 16.04.3 stick is corrupted.
The error message when re-purposing the stick is:

"The driver descriptor says the physical block size is 2048 bytes, but Linux says that it is 512 bytes."

It seems like usb-creator-gtk is using dd without specifying the correct blocksize corrupting the USB stick.

I've now lost 4 USB sticks on two different computers that I now can't format back to a usable stick.

Steps to reproduce:
Insert a blank USB stick into the USB port of the computer
Run usb-creator-gtk with an Ubuntu 16.04.3 ISO
Open gParted (parted, blkid, lsblk etc...)

"The driver descriptor says the physical block size is 2048 bytes, but Linux says that it is 512 bytes."

try to clean the disk with
dd if=/dev/zero of=/dev/$USBSTICK bs=2048; sync

again check the disk with gParted (or other disk utility)
"The driver descriptor says the physical block size is 2048 bytes, but Linux says that it is 512 bytes."

USB stick is destroyed.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: usb-creator-gtk 0.3.2
ProcVersionSignature: Ubuntu 4.4.0-89.112-generic 4.4.76
Uname: Linux 4.4.0-89-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CurrentDesktop: Unity
Date: Sat Aug 5 22:40:59 2017
InstallationDate: Installed on 2015-11-15 (628 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
SourcePackage: usb-creator
UpgradeStatus: Upgraded to xenial on 2017-06-16 (49 days ago)

Damiön la Bagh (kat-amsterdam) wrote :
Damiön la Bagh (kat-amsterdam) wrote :

So I finally found the answer after searching for a year!

First identify which drive letter the USB stick has received from the kernel

sudo parted --list
For example this USB drive is on Device Serial Disk h: (/dev/sdh)

Model: KINGSTON DataTraveler G3 (scsi) Schijf /dev/sdh: 4001MB
Use the information to wipe all the partition tables and data from the drive


sudo wipefs --all /dev/sdX
Make sure that you have chosen the correct USB stick for the value of X so you don't accidentally wipe your harddrive/SSD

Warning message

"The driver descriptor says the physical block size is 2048 bytes, but Linux says that it is 512 bytes." Means that the dd command in behind the nice GUI forgot to specify the bs=2048 option.


It's not that the unused space is wasted. The USB disk has been corrupted by USB Startup Disk Creator. For some reason USB Startup Disk Creator has become CD-ROM creator. It writes your USB-Stick to iso9660 format which is only intended for CD-ROM's. Since new computers don't come with CD-ROM players or writers anymore this is a regression bug

Damiön la Bagh (kat-amsterdam) wrote :

This regression bug also no long allows for persistent storage which was useful for saving settings on the LiveUSB or special modules/drivers that one would not have to re-download every time they load the LiveUSB.

sudodus (nio-wiklund) wrote :

Most linux distros provide hybrid iso files, which work both to create DVD boot disks and USB boot drives. This means that there will be an iso 9660 file system in the USB drive.

This is not wrong, it is a working system for a live-only drive and installer drive. The problem is that some tools do not understand, what it is, and complain, that is is corrupted. Fortunately there will be a new version of gparted in 17.10, which can recognize such drives.

sudodus (nio-wiklund) wrote :

I should add to the previous comment, that hybrid iso files are made to be *cloned* to USB drives (and memory cards) to make boot drives. The cloning process is very robust and likely to succeed. For this reason the Ubuntu Startup Disk Creator was revamped from a bug-ridden extracting tool to a simplified and robust cloning tool. The new version was introduced with Ubuntu 16.04 LTS.

There are cases when you want to use a USB pendrive both as a live drive and a storage device. This does not work with the read-only iso 9660 file system. In these cases you can use another tool, an extracting tool to create a persistent live drive.

Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in usb-creator (Ubuntu):
status: New → Confirmed
Simon P. (simpre) wrote :

Te problem is still existent in 17.10. The new version of gparted still cannot handle such devices.

sudodus (nio-wiklund) wrote :


The version of gparted in my Ubuntu 17.10 can handle such partitions; at least see them, as illustrated with the attached picture. Are you thinking of some other way to handle them?

Simon P. (simpre) wrote :

Sorry for the late reply, sudodus. I repaired my usb sticks with the solution described above in this bug report: sudo wipefs --all /dev/sdX and then just format them.

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