Using All the Storage on the SD Card
When an operating system is written to a Raspberry Pi’s SD card, the partition size is fixed by the image you install so you cannot use the whole of the SD card. This leaves little room for your own files.
To fix this, you need to run the raspi-config tool. This program automatically runs the first time that you boot your Raspberry Pi with a new SD card. You can also start it any time you need to adjust the configuration by opening a Terminal session and issuing the command:
$ sudo raspi-config |
Scroll down to the option expand_rootfs, and then use the cursor keys to press the Select button (Figure 1-9).
You will see a confirmation message, and then your Raspberry Pi will need to restart for the change to take effect.
You should now be able to use the full capacity of the SD card.
Discussion
Adjusting the root partition is definitely worth doing, especially for storing temporary files, but keeping your documents and personal files on a USB flash drive avoids the need to transfer files when you update your operating system.
See Also
You can find much more information about the raspi-config tool at http://elinux.org/RPi_raspi-config.