Problem with DD & Startup disk creator

I want to create a bootable USB drive for Chromium OS. I downloaded this image (direct link) and I want to put it on my 4 Gb USB. The IMG file is 2.6 Gb and my USB is 4 Gb, so there is space for the image.

When I run DD (dd if=ChromeOS.img of=/media/felixinx/0392-8145 bs=4M), I get dd: impossible d'ouvrir «/media/felixinx/0392-8145»: est un dossier as error (/media/felixinx/0392-8145 is a folder).

With Startup Disk Creator, I get an error : Impossible d'écrire l'image disque (/home/felixinx/Téléchargements/ChromeOS.img) sur le périphérique (/dev/sdb1). (Impossible to write image on the disk).

With sudo usb-creator-gtk, I get the same error, with a Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged. message on command line. (Yay! First error message in english!).

I don't know why is don't work.

Thanks

Your device is mounted. Your OS is using it, so it will not work correctly.

Also, you need to dd to a "/dev/xda" device, and not a mount point.

You will need to run:

sudo umount /media/felixinx/0392-8145

Then, run

blkid

to find out the device, maybe it will be /dev/sdb, so run:

sudo dd if=ChromeOS.img of=/dev/sdb bs=4M

Should work, if not, post the result. If you cannot unmount, just reboot, and don't open the file manager.