incremental disk wipe?

[rikona]

Hello Rashkae,

Friday, March 6, 2015, 11:22:38 PM, Rashkae wrote:

> On 15-03-07 01:09 AM, rikona wrote:
>> I was checking the timing of securely wiping large disks - looks like
>> it takes a looooong time. Is there a way to do this in smaller
>> 'chunks', that might complete in an hour or so, eventually filling up
>> the entire disk? I'm not hiding plots from NSA, so I don't need
>> extreme security - just enough to discourage easy-tech snoops. :-))
>>
> dd if=/dev/zero of=/dev/sdX bs=4M

> This will be as fast as you can go, but it will still take a modern 
> large hard drive several hours to finish.  But a drive that writes 
> 200MB/s still only writes 200MB/s... the drive can't multiple chunks 
> simultaneously.

Thanks to you and others for the replies. I wasn't thinking of
multiple chunks simultaneously - rather sequentially. Let's say I'll
be away from the comp for 30 min or so. How can I keep it busy for
JUST 30 min - no more, to do *part* of the wipe? Then, later, do
another 30 min, eventually wiping the entire disk?

I was considering filling the disk with huge numbers of innocuous
files, to replace the original data, then deleting all. I can do this
a bit at a time. Would this be reasonably secure? If so, how to write
a CL to generate many file copies, with different names, from 1-5
'base' files - but be able to limit how many are produced so one try
takes only about 20-40 min? [This is a USB2 disk, not fast] Would this
be much slower - enough to make it not a good choice?

Thanks...

-- 

 rikona