Shred file Shredder completely blocks file recovery

Deleting a file or reformatting the disk does not destroy sensitive data, and it can be recovered even if it is deleted. It's good to not delete some useless data, but it's dangerous if you delete financial data, bank account passwords, or classify company information that can't be completely removed, and this article will introduce some of the things you can do in Linux http://www.aliyun.com/zixun/aggregation/ 13835.html ">ubuntu tool for safely deleting files in the operating system.

Code:

Shred

Usage: shred [options] ... File ...

Repeated coverage < files make it difficult for even expensive hardware detectors to recover data.

Parameters that must be used with long options are also required when using short options.
-F,--force Modify permissions if necessary to make the target writable
-N,--iterations=n overrides n times instead of using the default 3 times
--random-source= file to remove random bytes from the specified file
-S,--size=n smash data to a specified byte fragment (use K, M and G as units)
-U, truncate and delete files after--remove overwrite
-V,--verbose display details
-X,--exact does not increase file size to the nearest block size
-Z,--zero last used 0 for overlay to hide overlay action
--HELP displays this help information and exits
--version output version information and exit

If the specified file is "-", smash the standard output data.

If you add the--remove (-u) option, the file is deleted. The default approach is to not delete files because it is common to overwrite device files such as/dev/hda, which should not normally be deleted. Most people use the--remove option when overwriting a generic file.

Warning: Please note that there is an important condition for using shred:

The file system overwrites the specified data in its original location. Traditional file systems meet this condition, but many modern file systems are not eligible. The following are examples of shred that invalidate or do not warrant a valid file system:

* Record structure or log file system, such as AIX and Solaris used file system (and JFS, ReiserFS, XFS, EXT3, etc.)

* Write data repeatedly and file systems that can continue even if a write action fails, such as using a RAID file system

* File systems that will be snapshot-logged at times, like receptacle Applicance Server for NFS

Installed by default

Of course, for home. The above approach is not ideal (including disk depletion). Here is a recommended method: folder encryption
Ecryptfs only save encrypted files on the hard disk. PlainText files and operations are cached in memory. The use of physical means is unable to obtain the original file.