Install isohybrid

Under Debian or Ubuntu the isohybrid utility is included in the syslinux package. To install it, you can execute the following command:

apt-get install syslinux

Find out the device name of the device

The device name should be something like /dev/sdb, /dev/sdc, etc.

If you are not sure about the exact device name, with GNOME, do the following:

Make sure that the USB stick or SD card onto which you want to install Tails is unplugged.
Open GNOME Disk Utility from the menu Applications ▸ System Tools ▸ Disk Utility
Disk Utility lists all the current storage devices in the left pane of the window.
Plug the USB stick or SD card onto which you want to install Tails.

A new device appears in the list of storage devices. Click on it.
In the right pane of the window, verify that the device corresponds to your device, its brand, its size, etc.

On this screenshot, the USB stick is a Kingston DataTraveler of 2.0 GB and its device name is /dev/sdc. Yours are probably different.

If you are not sure about the device name, you should stop proceeding or you risk overwriting any hard drive on the system.

Do the copy

Execute the following commands, replacing [tails.iso] with the path to the ISO image that you want to copy and [device] with the device name found in step 2.

isohybrid [tails.iso] --entry 4 --type 0x1c
dd if=[tails.iso] of=[device] bs=16M

Here is an example of the commands to execute, yours are probably different:

isohybrid '/home/amnesia/Desktop/tails-0.6.2.iso' --entry 4 --type 0x1c
dd if='/home/amnesia/Desktop/tails-0.6.2.iso' of=/dev/sdc bs=16M

If you are not sure about the path to the ISO image or if you get a No such file or directory error message, you can first type cat, followed by a space, and then drag and drop the icon of the ISO image from a file browser onto the terminal. This should insert the correct path to the ISO image in the terminal. Then complete the command and execute it.

If you don't see any error message, Tails is being copied onto the device. The whole process might take some time, generally a few minutes.

Once the command prompt reappears, you can shutdown your computer, and start Tails from this new device.

Troubleshooting

cat: /dev/sdx: No such file or directory

Then double-check the name of the device you found in step 2.

cat: /dev/sdx: Permission denied

You might also have committed a mistake in the device name, so please double-check it. If you are sure about the device name, this could be a permission problem and you could need to gain administration privileges before running the commands in the terminal. That could be:

isohybrid [tails.iso] --entry 4 --type 0x1c
sudo dd if=[tails.iso] of=[device] bs=16M

cat: tails.iso: No such file or directory

Then you surely have committed a mistake on the path to the ISO image in step 3.