A more extreme form of data wiping involves deleting a partition. The default method in most OSs simply creates the new partition header without cleaning out data in the original partition, even if changing the partition type. This can usually be overridden for a destructive format.

Create a new Ext4 partition by using the Linux mkfs command:

This command does wipe the partition. Confirm this by viewing the new partition with a hex editor. Then create a file as in earlier examples, save, and close it. Search for the file's text with the hex editor, then non-destructively-format the partition (by using the -Q option) to NTFS using mkntfs:

Confirm via the hex editor that the file contents still exist. Now recreate an NTFS partition, this time wiping the data:

As can be seen in the output, mkntfs has overwritten the partition with zeros. Double-check this with the hex editor again.

Fig. 4.1: Seeking the file after a "quick" format (left), and after a destructive format.

Although the file is inaccessible through the usual way after a quick format, the data within the file remains. A destructive format, however, does obliterate the data, as seen in Fig. 4.1.