FYI: Wiping a hard drive really clean

[Net Llama!]

On Mon, 6 Jun 2005, Michael Hipp wrote:

> 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.

/dev/urandom is _very_ slow.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Lonni J Friedman                        netllama at linux-sxs.org
LlamaLand				http://netllama.linux-sxs.org