Resize Raspberry PI partition.

First you need to change the partition table with fdisk. You need to remove the existing partition entries and then create a single new partition than takes the whole free space of the disk. This will only change the partition table, not the partitions data on disk. The start of the new partition needs to be aligned with the old partition!

Start fdisk:

sudo fdisk /dev/mmcblk0

Then delete partitions by selecting d, and create a new with n. You can view the existing table with p.

• p [Enter] to see the current start of the main partition
• d [Enter] 2 [Enter] to delete the main partition
• n [Enter] p [Enter] 2 [Enter] to create a new primary partition
• Now you need to enter the start of the old main partition and then the size ([Enter] for complete SD card). Use the initial p output from above!
• w to write the new partition table

Now you need to reboot. After the reboot you need to resize the filesystem on the partition. The resize2fs command will resize your filesystem to the new size from the changed partition table.

resize2fs /dev/mmcblk0p2

This will take a few minutes, depending on the size and speed of your SD card.

When it is done, you can check the new size with:

df -h

Source: http://minibianpi.wordpress.com/how-to/resize-sd/