Plug the key on a USB port of your computer and turn on your computer. When the computer boots, you have to ask it to boot on the USB key (usually, you have to press F2 or a similar key at startup, and modify the boot sequence such that the USB key is considered before the hard disk of your computer).


If you plan to mount your hard disks from the live USB, please ensure that your host system is not hibernating, but completely shut down, otherwise it might not notice filesystem changes when you use it again, and you could lose important data!

Directories of the USB key

If you plug the key on an already working computer, you will see the following directories on its root:

Login / Password

If for some reason the live USB key asks you for a login and password:


You can contact the author of this USB key by clicking on the "Tools" icon on the desktop, and then the "Contact" icon, you will be able to let a message and the genealogy of the USB key will be transmitted. Don't forget to let your e-mail address if you want to be contacted by the author of the USB key. You can also send him an e-mail to the address

Change the keyboard layout

If you use more than one keyboard layout, you can switch between them easily by adding a keyboard switcher on the top bar of the screen. For this:

Change the system language

This will take effect after restarting your session, which you can do immediately by clicking on "Yes".

Clone or upgrade the USB key

This USB key is able to duplicate itself on any other USB key whose size is at least 4GB. For this, it suffice to:


All the data of the new USB key will be lost !

If there is enough free space on the destination key, you may be asked if you want to upgrade instead of clone. The upgrade is useful if you want to keep your personal data that is already on the USB key (unlike the clone feature, your USB key won't be reformatted), in particular if you have an older version of the Sage Debian Live on the destination key, it will be upgraded and your previous work with it will still be available.

Personal data and shared data

By default, personal data are stored on the /user directory of the USB key (which corresponds to /home/user in the live system), in particular the Sage worksheets. Unless you do it in purpose, your personal data won't be copied when you duplicate the USB key. However, the data put in the /share directory, which is accessible from the desktop, will be transmitted to the next USB keys. Therefore, put into the /share directory only public data of general interest.

Keep system changes

If you change something on the system, it will be lost at next reboot (only the changes in the /home directory are persistent). If you want to keep system changes done in some directory for further reboots, open a terminal and type:

keep dir <directory>

Install new software

You can install a Debian package as usually with sudo apt install <package>, and you will benefit from the software during all your session. However, it will not be available after the next reboot. If you want to install a package permanently on the system, open a terminal and type:

keep install <package1> <package2> ...


To use Sage, click on the "Mathematics" icon on the desktop and then on either on "Sage notebook" or "Jupyter notebook" depending on your favorite interface. For the Sage notebook, provide an admin password of your choice (twice). Some documentation (pdf books) is available on the Documentation directory on the same group of icons.