drakdisk or diskdrake This tool You can start this tool from the command line, by typing drakdisk or diskdrake as root. is very powerful, a tiny error or a cat jumping on your keyboard can lead to losing all data on a partition or even to erasing the entire hard disk. For that reason, you'll see the screen above on top of the tool screen. Click on Exit if you're not sure you want to continue. If you have more than one hard disk, you can switch to the hard disk you want to work on by selecting the correct tab (sda, sdb, sdc etc). You can choose from many actions to adjust your hard disk to your preferences. Wiping an entire hard disk, splitting or merging partitions, resizing them or changing the filesystem, formatting or viewing what is in a partition: it is all possible. The Clear all button at the bottom is to erase the complete disk, the other buttons become visible on the right after you click on a partition. If you have an UEFI system, you can see a small partition called "EFI System Partition" and mounted on /boot/EFI. Never delete it, because it contains all your different operating systems bootloaders. If the selected partition is mounted, like in the example below, you cannot choose to resize, format or delete it. To be able to do that the partition must be unmounted first. It is only possible to resize a partition on its right side To change a partition type (change ext3 to ext4 for example) you have to delete the partition and then re-create it with the new type. The button Create appears when a disk empty part is selected You can choose a mount point that doesn't exist, it will be created. Selecting Toggle to expert mode gives some extra available actions, like labeling the partition, as can be seen in the screenshot below.