Clearing the unallocated disk space

[jd1008]

On 11/16/2014 12:09 PM, Tom Horsley wrote:
> On Sun, 16 Nov 2014 12:04:31 -0700
> jd1008 wrote:
>
>> Before sending the drive for warranty service, what is the best way to
>> clean the unallocated blocks?
> A way is to run as root "cp /dev/zero tempfile" for one "tempfile" per partition
> until the cp fails due to running out of disk space. That will allocate all
> free space and write zeroes to it.
I had read somewhere that THAT is not enough.
I recall that in fc12 there was a util that would scavenge all
free space (albeit, in manageable chunks at a time), then
clean them using several different method.
I am unable to recall that util's name :(