

DAWN: Durable Array of Wimpy Nodes (2011) [pdf] - sp332
http://www.ssrc.ucsc.edu/Papers/ssrctr-11-07.pdf

======
dshr
There's already at least one startup building a flash controller intended to
enable a DAWN-like architecture using TLC (triple-level-cell) flash, NxGnData
[http://www.nxgndata.com/](http://www.nxgndata.com/) \- more details on my
blog at [http://blog.dshr.org/2014/08/is-this-dawn-of-
dawn.html](http://blog.dshr.org/2014/08/is-this-dawn-of-dawn.html)

Full disclosure - I am a co-author of the DAWN paper. The key point of the
DAWN paper is the same as the FAWN paper, that conventional architectures with
large amounts of storage paired with powerful CPUs can be out-performed on
many axes by large numbers of small nodes each with a small amount of both
storage and computation. Flash is the available memory to do this with now, it
will be replaced eventually by better solid-state memories (e.g. Phase-Change
Memory) but the architecture will remain. See also Seamicro
[http://www.seamicro.com/](http://www.seamicro.com/) for a current example in
the FAWN-like space.

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wmf
The point of this paper rests on an unfair cost comparison of local flash vs.
S3. We know that S3 is much more expensive than local disk. If they compared
local flash against local disk (e.g. Pergamum), disk would still win.

They have a newer paper that sounds better:
[http://www.ssrc.ucsc.edu/pub/gupta25-mascots.html](http://www.ssrc.ucsc.edu/pub/gupta25-mascots.html)

~~~
kelanis
Erm, yes and no. We focused more on the medium than the exact architecture. In
point of fact, we directly say we draw heavily from the Pergamum design. The
high-order bit, so to speak, is that disks suffer from a variety of
electromechanical problems that flash and other SCM's don't suffer from,
making it more appealing as a long term storage medium. Its (potentially)
longer 'shelf-life' and lower power requirements mean it would likely have
lower total cost of operation than a disk based approach.

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gojomo
They've buried the lede under cute terminology, like "wimpy nodes" and
"storage class memory (SCM)".

The main thrust of the paper is that under certain assumptions, flash/solid-
state/etc memory ("storage class memory") may already be competitive with
spinning hard disks or tape for long-term archival storage of bulk data.

~~~
kelanis
The "wimpy nodes" was a bit too cute for my tastes, but storage class memory
is actually a fairly common term in the research community. The "wimpy nodes"
was meant to be a coat-tail grab for the FAWN project, which we (disclaimer: I
am one of the authors) heavily drew from in addition to the Pergamum project.

~~~
gojomo
Thanks for the clarification. As an anecdotal data point, I didn't recognize
the _storage class memory_ term, even though I'm quite interested in these
topics, sometimes reading related research papers.

The abstract would have been more helpful had it alluded to the definition,
for example "…of storage class memories (SCMs), such as flash memory, has
been…".

Similarly, the term isn't defined on first use, and even following the
footnote which strongly suggests definition/discussion of the same topic
elsewhere ([21]), that particular term doesn't appear in the referenced
Rosenthal "Keeping Bits Safe" article.

(Now I know, but I'm still not a fan of the term. At these levels of abstract
analysis, it's all 'memory', and it's all being considered for 'storage', so
_storage class memory_ lacks vividness/contrast.)

~~~
vicaya
The industry term is NVM, which refers to all classes of non-volatile memory,
typically high density ones.

How do you like Crystal Ridge?

~~~
gojomo
NVM makes slightly more sense to me than SCM.

Crystal Ridge? (If you mean the nursing facility, still hoping for a more
Rainbows End arrangement.)

