
Facebook's new optical storage solution [video] - riledhel
https://www.facebook.com/photo.php?v=10152128660097200
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nicholasjarnold
Another benefit of this system is that the storage media is immune
electromagnetic pulse. So, even in the case of a large-scale EMP event our cat
pictures and network graphs will remain intact and recoverable. :)

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tlrobinson
I assume SSDs are screwed by EMPs, but how does magnetic media fare (the
tape/disk media itself, not reader/writer electronics)?

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ricardobeat
Wiped.

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crazygringo
Can anyone knowledgeable explain why they use Blu-Ray instead of tape backup?
When would an organization use Blu-Ray, and when wouldn't then? Is this
reflective of any kind of general trend?

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kitcar
I'm not knowledgeable, but some total guesses:

1) As blu-ray is a consumer product its probably manufactured in greater
quantities than backup grade tapes, and therefore can be had lower in price,
and there are more vendors to source them from. Similarly the drives
themselves are cheaper.

2) Tapes aren't random access, therefore it's slow and cumbersome to retrieve
single files.

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jonny2112
3) IIRC most tape storage technolgies are closed source. FB has been heavily
pushing their open compute project. Using BDs get them past a lot of licensing
problems.

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wmf
I don't think LTO is any more proprietary than Blu-ray.

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protomyth
and LTO has way less licensing problems than Blu-ray and LTO-6 has a max of
2.5TB. LTO is also guaranteed to to read tapes from 2 generations earlier and
write one generation earlier. Blu-ray has no such long term guarantee.

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fastball
My hopes were dashed when I realized that this wasn't a new type of optical
hard disc, like holographic drive technology or something.

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ricardobeat
Maybe in a couple years: [http://rt.com/news/5d-nanostructured-glass-optical-
memory-94...](http://rt.com/news/5d-nanostructured-glass-optical-memory-941/)

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ksec
With Big Data Everything, we really need an Optical Storage System like Blu
Ray but with 100x to 1000x the capacity.

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drcross
No comment on the access time and having only one drive means reading only one
disc at once. This puts this storage solution in the realm of "I don't need
this data within an hour" so I presume the application this system acts as
redundancy for failed disks.

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baddox
The guy was very explicit that this is a cold storage solution. Probably
"backups of backups."

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NatW
The Facebook open computer definition for "cold storage":

"where data is stored on disk but almost never read again, like legal data or
backups of third copies of data — keep on increasing dramatically, there are
huge demands for developing some form of cold storage system with the highest
capacity and the lowest cost."

source:
[http://www.opencompute.org/projects/storage/](http://www.opencompute.org/projects/storage/)

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nivla
Are these Blu-ray disks rewritable? If so, wouldn't this be a great tech for
Amazon's Glacier service? I believe they currently depend of costly tape
drives to store data.

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akg_67
Each LTO-6 tape cartridge stores 6TB of data. Each quadruple layer Blue-ray
disk stores only 128GB. I am surprised that FB went with Optical Disk instead
of Tape.

Optical jukeboxes/libraries for MO/DVD/CD used to be popular a decade or so
ago and now considered antique. There is just not enough density with optical.

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sargun
My guess: 1) Lower cost for drives (commodity drives). 2) The ability to
(easily) seek to an arbitrary location on disk 3) Cost of BD burners are
<$100; Cost per GB of disks is $0.025/GB. LTO-6 drives are $1000+, and cost
per GB is around $0.012/GB. -- I think the cost works out actually, especially
as the cost of blu-ray is still falling.

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kraemate
Does anyone know what data is Facebook trying to archive? Old user posts? But
that doesn't fit this usecase because of the high latency.

Or maybe its just a nice content delivery mechanism to the NSA. Just ship a
bunch of blue-rays instead of pesky optical fiber interception.

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jonny2112
FB is required by law to store all its credit card transactions that every
singal FB ads account has for 6 years. (So are other US based companies that
process credit cards)

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kraemate
Surely, credit-card info can't span 100s of terabytes, even if they record
each and every transaction.

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shawabawa3
backups of images/videos/posts/everything

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dsl
Facebook has built a novel implementation, but this isn't a new idea or
product. Similar to how they used to buy servers and now build them to spec,
they probably used to buy these and now design and build them.

[http://www.disc-group.com/products/bd-series-benefits/](http://www.disc-
group.com/products/bd-series-benefits/)

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gatehouse
After I saw this on James Hamilton's blog the other day I did a quick check of
BD-R versus 4TB HDDs cost per GB. Using whatever I could find after about 5
minutes of looking around, I came up with $0.05/GB for both types of media.

If anyone can provide a link to BD media for sale at a price that make this
economical I'd be interested to know.

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glomph
The saving is in power consumption for cold storage.

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mapt
Are modern hard drives not rated to survive very long in spun-down, powered-
down condition?

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treelovinhippie
Any guess on the total storage capacity in that rack and comparison to a
similar sized magnetic storage?

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nuclear_eclipse
From the video: 24 magazines/rack * 36 cartridges/magazine * 12
discs/cartridge * 50 GB/disc = 518TB/rack. Based standard dual-layer discs. I
cannot comment on storage of our traditional spinning-disk racks.

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derekp7
Backblaze Pods are about 180TB, so 1800TB per rack. And a whole lot of power
consumption.

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callesgg
I was expecting some kind of optical fiber storage with reflecting crystals
and shit.

This was a bit disappointing.

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jpalomaki
I might be interested in cloud backup service which would backup my "keep
forever" stuff, put them to optical disc and then mail the discs to me when
they fill up.

Could be also an add-on service to existing online backup business.

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polskibus
What about bit rot though? Some of my dvdr are no longer readable after 5 yrs,
stored in very good conditions. Hdd backup, esp. with Zfs can provide very
good bit rot protection.

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randartie
These are high grade guaranteed for 30+ years. There's also 1000 year grade
blu rays out there.

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polskibus
I had failures of both "archival" quality DVDs and SD cards before, just after
a year or two after last backup.

Do you have any links on the methodology used to measure the 30+ or 1000yr
grade for a blu-ray ?

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hsshah
FB: How can you get a consumer version of this so that you don't have to use
Amazon Glacier for personal data archival?!

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cordite
I did not know that they made disks that are certified for long term storage
like that.

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rld
At 1:55 he says "FRID'd", he meant RFID'd, right?

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chm
Still magnetic storage however you read/write the data...

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sneak
Flash required, so it won't play here.

Really, Facebook? It's 2014.

