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Linux dd – Wiping a disk with /dev/zero
The most important and dangerous part of any PC is the hard drive. Dangerous, not because of any physical risk, but because of the data on it. Privacy information, important documents, sensitive photos: it potentially has everything. That's why it's important to securely erase hard drives that you no longer use.
However, don't rely on the basic formatting tools that come with your operating system. In most cases, these tools won't erase your data, making it possible to recover your files. You can solve this problem by "zeroing" a hard drive sector by sector. Here's how to zero-format a hard drive using a Linux live environment.
Some of the technical terms are a bit ambiguous, but "zero fill" means just that. From start to finish, your hard drive is filled with zeros, erasing all traces of previous files underneath.
