FYI: Wiping a hard drive really clean

[Michael Hipp]

Matthew Carpenter wrote:
> root at sherlock:/home/cmnc507 # time dd if=/dev/random of=/dev/sdb
> 30019584 bytes transferred in 705308.439847 seconds (43 bytes/sec)
> 
> root at sherlock:/home/cmnc507 # time dd if=/dev/zero of=/dev/sdb bs=1048240
> 1000237400064 bytes transferred in 61791.766641 seconds (16187228
> bytes/sec)

43 vs. 16187228 Bytes/sec. A difference of a mere 376,447x. Is that due 
to the calculations in /dev/random? I would have thought that would be 
minuscule compared to the speed of spinning media. Strange.

Michael