Within the Linux operating-system(that is free), the super user(root) has raw use of disks and partitions around the disks within the machine. The overall idea would be to write random data generated through the Linux operating-system, towards the hard disk drive.
The problem frequently arises where a person must discard a classic computer, but doesn’t want the information around the disk from the old computer to become accessible if a person retrieves it via dumpster diving. There may be data kept in the motherboard or a few of the peripherals, but that’s past the scope want to know, Ideally, the disk platters ought to be physically destroyed, but because of hardware or cost constraints, this may not necessarily be possible.
A totally free method to wipe the information from the disk involves utilizing a bootable Linux disk to create random data towards the disk multiple occasions. This is actually the general procedure:
Boot the device off an active Linux disk, for example, Knoppix, BackTrack or Gentoo installation disk
Find out the dev node in /dev akin to the disk that will be easily wiped.
Use dd to see pseudo-random data in the kernel and write it towards the disk.
1) Booting off an active Linux Disk
Live Linux disks are CDs/DVDs that the compatible computer could be booted from instead of booting in the Operating-system placed on a tough disk. Live Linux disks are helpful once the user really wants to make use of the computer without departing any trace behind or customize the hard drives within the computer without booting the Operating-system placed on them. BackTrack Linux is such Live distribution of Linux and could be downloaded free at http://world wide web.backtrack-linux.org/.
2) Locating the Dev Node
One method to find the correct dev node would be to match the known capacity of the disk in bytes with this reported in /proc/partitions. There must be some symbol of capacity around the sticker from the disk. Otherwise, the model no. located on the sticker from the disk could be looked on the internet and the capability is available this way. In Linux, both raw disks and also the filesystems on individuals disks appear as dev nodes in /dev. Because the goal would be to wipe the entire disk as opposed to just a partition, the disk’s dev node, as opposed to the partition’s dev node, can be used. The disk and also the partitions indexed by /proc/partitions could be differentiated by searching in the last character within the name. Usually, partitions finish inside a digit, while disks finish inside a letter. The dev node to make use of may be the file in /dev with a similar name because of the preferred line in /proc/partitions. For instance, soda refers back to the first disk, while sda1 refers back to the first partition on the first disk. Within the example below, the PC only has 1 hard disk drive, soda. The soda disk has 2 partitions, sda1 and sda2. To be able to wipe the disk, the /dev/sd dev node is going to be used.