shred
shred is a program that is supposed to enable secure deletion of files on data carriers under Unix systems . Various methods such as multiple overwriting with bit patterns or random values are used to make it difficult or (from a practical point of view) to restore deleted data. The command belongs to the GNU Core Utilities .
restrictions
Due to technical circumstances, shred cannot develop its effect on all file systems . Data cannot be reliably and safely deleted in the following situations, among others:
- If the file system implements copy on write semantics, for example ZFS
- If a log-structured or " journaled " file system is used, for example JFS , ReiserFS and XFS .
- If the files were stored on a RAID system (a hard disk array).
- For file systems, the snapshot (snapshots) create.
- For compressed file systems.
- For network file systems .
- In the case of file systems on certain flash memories , where wear-leveling algorithms ensure that when existing data is overwritten, it is stored at a different physical address in the memory.
See also
- Wipe , a similar software
Different meaning
The term shred is also used for a certain type of guitar playing , see shredding .
Web links
-
shred(1): Overwrite a file to hide and optionally delete its contents - Debian GNU / Linux Executables or Shell Commands man page - Command description in the GNU Coreutils documentation
- shred for Win32 in the GnuWin32 Coreutils for Windows