[CentOS] erase disk

Hi.

I have a CentOS server (a Dell 860) with two drives in it.

One is running CentOS 6.4 which I want to keep & the bigger 400GB drive 
has Debian 7 on it which I want to erase & use for backups.

Which is the best way to go about achieving my intended goal? The Debian 
drive is not mounted when Centos is booted.

Any help appreciated.

Cheers,

    Phil...

-- 
currently (ab)using
Arch Linux, CentOS 5.9 & 6.4, Debian Squeeze & Wheezy, Fedora Spherical & That Damn Cat, Lubuntu 12.10, OS X Snow Leopard & Tiger, Ubuntu Quantal, Raring & Saucy
GnuGPG Key : http://phildobbin.org/publickey.asc