For Raspbian Wheezy Linux® image, you must manually extend the partition space on the SD card as described in this section. For all other Raspbian images, the partition space is automatically extended.
The firmware update for Raspberry Pi™ hardware burns a Raspbian Wheezy Linux image on an SD card. This Linux image uses approximately 3.5 GB of the SD card. If you use an SD card whose size is greater than 3.5 GB, some unused space remains on the SD card. To use the full capacity of the SD card, you can use the “raspi-config” program available with Raspbian Wheezy.
This command sequence launches a PuTTY SSH shell to your Raspberry Pi hardware.
Log in to the Raspberry Pi hardware with your user name and password.
On the raspi-config menu, select the move 'expand_rootfs' option, and press Enter.
On the raspi-config menu, select the Finish option, and press Enter.
When the board finishes rebooting, raspi-config automatically resizes the Linux partition on the SD card to occupy the remaining space.
The boot process takes longer than usual for larger SD cards.