Securely erasing a storage device
sudo shred -v /dev/sdX
sudo shred -v -n1 -z /dev/sdX
sudo apt-get install gparted gksu gparted
How Do I Permanently Delete Files From My Hard Disk? | PCWorld
How Do I Permanently Delete Files From My Hard Disk?
Follow these simple instructions to completely remove files from your drive.
Did you know that when you "delete" files from your computer, they can still remain on your hard disk? In many cases, deleted files can be recovered with little effort because most computer operating systems will only delete links to the data so they no longer appear to you, but the actual data remains on the disk. Getting access to the deleted data is as simple as restoring the links.
This method of deletion is fine for most circumstances--where security is not an issue--but you wouldn't want some people to recover your financial statements or medical records. For sensitive data, you need to make sure that your computer overwrites both the links to the information and the information itself.
Step-by-Step: Using Eraser
To make sure a file is truly gone, a number of tools are available. Eraser is a free and easy-to-use solution that will overwrite your private information with random patterns until the data is no longer recoverable. It works with nearly every version of Windows and offers a number of methods of overwriting your data, including methods approved by the Department of Defense.
Once installed, Eraser integrates nicely into Windows. Whenever you want to securely erase your data, follow these steps.
1. Navigate to the files or folders that you want to securely erase.
2. Right-click on the files and/or folders and an Eraser menu will appear.
3. Highlight and click Erase in the Eraser menu.
Eraser will automatically create the secure erase task and execute it immediately. You will be notified in a popup window when the task is complete and the files are permanently erased.
Eraser has a number of settings and options that you can configure, including securely deleting recycle bin contents and scheduling and automating secure deletion tasks.
Step-by-Step: Using SDelete
For users who don't need graphical interfaces, Microsoft has a downloadable command-line tool called SDelete. Here's how to use this tool.
1. Click Start > Run... , type cmd and press OK or Enter (Return). (Windows Vista and Windows 7 users can just click Start and type cmd in the Windows Search box.)
2. Navigate to where you have SDelete downloaded. For example, if it's located at C:\cmdtools, typecd C:\cmdtools, and press Enter.
3. Now type sdelete <path to file or directory>, and press Enter, where <path to file or directory> is a standard Windows path. For example, to delete C:\mysecuredata.txt, you would type sdelete c:\mysecuredata.txt, and press Enter.
4. Once they're deleted, you will receive confirmation that your files or folders have been permanently deleted, and you're done!
Now that you have the right tools for the job, you can feel confident in knowing that your data has actually been removed from your hard disk and will no longer be recovered by anyone (not even by you).