zeroing out the cloud image filesystem

[R P Herrold]

On Tue, 21 May 2013, Bill Nottingham wrote:

> Matthew Miller (mattdm at fedoraproject.org) said:

>>>> 2) I also commented out the "Zeroing out empty space" 
>>>> postinstall stuff, because it drastically increases the 
>>>> image build time for not much benefit, IMHO.

>>> One time image build cost vs. whatever benefit multipled 
>>> by every time the image is used. :)

>> To put some numbers behind it, the compressed qcow2 image with the dd to
>> zero empty space is 215M out of appliance-creator. Without it, it's 242M.

post install is the wrong place, agreed.  Pre-build of an 
image is not

There are privacy implications in not blanking a VM image. 
In some LVM setups, one may pick up a previous image's slack 
space still containing live data.  A cautious provider does 
not provide an image with anything worth trolling (trawling 
<?>) through

Matt,

What timing is seen running (pre install):
 	shred -n 0 -z /path/to/image
compared to that 'dd' approach quoted?

-- Russ herrold