If you need to reuse or recycle a server it is critically important that any sensitive data on the hard drive is erased and rendered completely unrecoverable. There are methods of rebuilding and recovering data even from formatted drives, so it’s advisable to use some form of specialised deletion tool.
DBAN (Darik’s Boot and Nuke) is an open source application used to securely erase data from a hard drive. It does this by overwriting the entire drive with pseudorandom code, making data recovery as close to impossible as is practically achievable.
It can be downloaded from the project page on Sourceforge at:
Install it on a CD/DVD or USB drive and boot the server up from it. It will load a DOS-like text screen listing several options. In it’s most common usage, just typing ‘autonuke’ will start the process running. As it writes to the whole drive, this can take a long time to complete on large disks.
In addition to servers, DBAN can also be used to erase the drives on desktop machines.
More information can be found on the official website: www.dban.org