
How to fit 1,000 terabytes on a DVD - clicks
http://theconversation.com/more-data-storage-heres-how-to-fit-1-000-terabytes-on-a-dvd-15306?utm_medium=email&utm_campaign=Latest+from+The+Conversation+for+20+June+2013&utm_content=Latest+from+The+Conversation+for+20+June+2013+CID_06ee2f136721194be78210c407225a91&utm_source=campaign_monitor&utm_term=More%20data%20storage%20Heres%20how%20to%20fit%201000%20terabytes%20on%20a%20DVD
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nknighthb
I certainly wouldn't mind returning to a world where inexpensive, easily-
labelled optical disks could hold relatively large amounts of data.

When HDDs were generally no more than a few gigabytes, I could basically stick
a compressed backup of my PC on 1-2 CDs, write a date on them, and shove them
in a box. It was incredibly convenient and offered good peace of mind. In
fact, I just recently recovered some important data from the late 90s off one
such CD.

~~~
dalore
You must take good care of your CDs, or they made better quality ones back in
the 90s as most of them degrade after 10 years or less.

[http://en.wikipedia.org/wiki/CD-R#Lifespan](http://en.wikipedia.org/wiki/CD-R#Lifespan)

~~~
nknighthb
I've never seen a serious study on the subject (at least not in English), only
anecdata, so I've never been sure how much veracity to assign to claims of the
commonality of CD-R degradation. It wouldn't surprise me if 90s-era discs were
higher quality, though -- for my own anecdata, I've had only one batch of CD-
Rs ever show evidence of degradation, and it was one of the last I ever bought
and seriously used in the early 2000s.

I've never seen a problem with DVD-Rs, but I didn't use nearly as many of
those. I haven't written new optical disks for practically anything other than
OS installation media since ~2003/2004, and in the last few years I've rarely
even done that.

(And I never made the hop to BD-R. From a data storage perspective, I found it
pretty much obsolete on arrival.)

~~~
abawany
My anecdote re. BD-R: I got the Verbatim "good" discs (made in Taiwan, good
dye technology - sorry I forgot the specifics) a while ago and used them to
backup data (that fortunately had backups to other places as well). Months
later, tried to read them. No dice. I was shocked as I thought BD-R's were
built more robustly than DVD+-R's. BTW, this is true of all 3 discs that I
tried, albeit they came from the same 50-pack.

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quarterto
Is the article using "DVD" to mean "a DVD-sized disk", or does it actually
mean DVD? Either way, it's impressive.

~~~
Noppix
DVD-sized disk.

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weinzierl

        [...]using a two-light-beam method, with different 
        colours [...]
    
       The two beams were then overlapped. As the second   
       beam cancelled out the first in its donut ring, the 
       recording process was tightly confined to the centre 
       of the writing beam.
    

How to they get the two beams (of different frequency) to cancel out each
other?

~~~
gjm11
This isn't optical interference (in which beams with different wavelengths
couldn't affect each other, as you say).

Instead, the recording media has a response that looks kinda like
intensity(lambda1) - intensity(lambda2). Then they combine a spot (bigger than
they want) of wavelength lambda1, with a "doughnut" of wavelength lambda2. The
net response of the recording media is then "spot minus doughnut" and if they
choose the parameters right that looks sufficiently like a smaller spot.

You can see the full article at
[http://www.nature.com/ncomms/2013/130619/ncomms3061/full/nco...](http://www.nature.com/ncomms/2013/130619/ncomms3061/full/ncomms3061.html)
for more details.

~~~
weinzierl
That makes sense, thanks.

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knodi
Sure you can put 1,000TB on it but whats the read speed?

There is a reason both PS4 and XboxOne will require to install the game even
if the Bluray can hold all that data and more. High density optical formats
are slow to read.

At 16x Bluray only reads at 72MB/s.

~~~
nknighthb
Higher densities bring faster reads. I would assume this technology would be
many times faster than the raw linear read performance of Blu-ray, as Blu-ray
was much faster than DVDs, and DVDs much faster than CDs.

72MB/sec, BTW, is substantially faster than best-case USB 2.0, which many
people still use for backups and file transfers.

The primary limiting factor for games isn't the 72MB/sec linear read speed,
it's seek time/random read performance.

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kailuowang
This might help save billions of tax payer dollars spent by the NSA.

~~~
microcolonel
Government budgets don't go down, they'll just find a way to spend more at
their predicted curve.

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tlrobinson
So according to Brewster Kahle's estimates for storing all US phone calls
([http://blog.archive.org/2013/06/15/cost-to-store-all-us-
phon...](http://blog.archive.org/2013/06/15/cost-to-store-all-us-phonecalls-
made-in-a-year-in-cloud-storage-so-it-could-be-datamined/)), it would only
take 272 of these theoretical DVDs per year!

Of course there's a big tradeoff in latency (on the order of 10s of seconds to
switch DVDs) and throughput (unknown), but properly indexed I'm sure it would
still be extremely useful, and extremely cheap.

Imagine fitting all of that data in this little box:
[http://gizmodo.com/5321357/sony-finally-popping-400+disc-
blu...](http://gizmodo.com/5321357/sony-finally-popping-400+disc-blu+ray-
megachanger-so-dont-toss-your-dvds-yet)

~~~
chopsueyar
The idea of cloud storage or streaming audio/video sounds even less enticing.

~~~
samstave
This would be for spooling archival data to, not to stream from. This will
have great impact on the NSA's noble desire to keep a living record of all
human communications!

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ChuckMcM
Its too bad they don't address the media question. While its great to write 9
nanometer dots if your media fills them back in after a while, well its not as
useful.

I've got media from the 80's (gold backed) that is still readable with no
errors, and some that is aluminum (silver) backed and is readable with error
recovery.

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rtb
Otherwise known as a petabyte?

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ajays
True; but this is a PopSci article. Most people who read such media are
probably not familiar with the term. They'll probably think of a petting zoo
when they read "petabyte".

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batbomb
Using this with archival grade DVD-Rs would make big science much cheaper,
accessible, and reproducible. Imagine the LHC fitting all their data into a
briefcase, and just sending it to whoever asked for it. Of course, the real
problem would be writing bandwidth.

Using archival grade media and write redundancy + ECC, you could decrease the
size of what you put on a disk to just 10TB and probably hit a sweet spot
between massive amounts of storage, exceptional reliability, and increased
bandwidth.

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bloaf
Wouldn't that have huge problems with durability? A single scratch could
render a lot of data unreadable.

~~~
Selfcommit
Would it really be so hard to engineer these "disks" with an outside layer of
plastic protection?

I have a mock-up here:
[http://i.imgur.com/DbV5ByR.jpg](http://i.imgur.com/DbV5ByR.jpg)

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NatW
Quick back of the envelope: 1 of these ~= 1333CDs or 212DVDs The increase from
a CD to a DVD was by a factor of ~6.26. This is 33.8 times that factor of
increase.. but no word on the speed of reading/writing in this article.. which
I assume will be slow.

~~~
batbomb
Your back of the envelope is off by a factor of 1000.

~~~
samstave
He only had access to a small envelope.

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venomsnake
That is fine for writing. How are they gonna read the thing. Also isn't
exposure to direct sunlight going to obliterate everything inside?

~~~
vxNsr
They could still use this tech for HDD, right now a HDD uses similar tech to
DVD just with more precision, this would make things still more precise.

(though I don't really know about it being obliterated when exposed to
sunlight)

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tocomment
I wonder if researchers are also looking into meta materials as a way to
increase storage density on optical discs?

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voyou
Spendthrifts! They could have used a CD and increased the capacity from 600MB
to one petabyte.

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ibudiallo
I wonder how long it will take to burn one cd on a typical desktop computer.

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csense
I can store 1024 terabytes on a DVD today, entirely in software, no innovative
hardware based on new engineering principles necessary:

    
    
       dd if=/dev/zero bs=1024 count=1T | pv -c -W | gzip -c9 | pv -c -W > big.gz
    

I'm pretty sure the resulting big.gz will fit on a DVD with plenty of room to
spare.

You may need to sudo apt-get install pv if you don't have that incredibly
useful utility already. You may also need several hours of CPU time...

EDiT: Downvoted within two minutes? HN needs to get a sense of humor...

