stressdrive

writing random data on it, rather than zeroing it out, will avoid block de-duplication and successfully completely fill it up. Here is a tool written for exactly that (although not intended for securely erasing a drive, it will have that effect too): https://github.com/rentzsch/stressdrive

EDIT: I see now that you say "It read back the data like his stresstest program does" and probably mean "It won't read back data..." While your command is a good way to quickly write random data to a drive, note that it doesn't match the functionality of his stressdrive program, which keeps a checksum of the random data it wrote, and then reads back the data from the drive to verify the checksum. Not that that would be hard to do with a few pipes. Note that the docs for stressdrive[1] mention this: "Pshaw! I could do this with dd, /dev/random & shasum!" Indeed you could. I prefer a minimal focused tool whose operation is fixed, its source simple+readable and offers good built-in progress reporting. [1]: https://github.com/rentzsch/stressdrive