How can I Wipe files or partitions in Linux?

[GrumpyOldMan]

If you just do:

dd if=/dev/urandom of=/dev/sdX

dd will use a default block size, which is quite small, and so the process will be very slow. Use the bs option to specify a larger block size:

dd if=/dev/urandom of=/dev/sdX bs=1M

Unless you have several days to wait, of course.

 

[Videodrome]

The Shred command is also useful for individual files or whole partitions and drives.