

What Every Data Programmer Needs to Know About Disks - frsyuki
http://www.oscon.com/oscon2011/public/schedule/detail/20137

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wazoox
Paint me unimpressed. "eat my Data" was a way, way better and deeper
presentation:

<http://www.oscon.com/oscon2008/public/schedule/detail/3172>

Get the presentation here:
<http://flamingspork.com/talks/2007/06/eat_my_data.odp>

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Swannie
Thank you for that link. This is a far more interesting presentation than the
OT. (Though it does assume some prior knowledge, like what fsync is, etc.)

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CJefferson
This talk totally failed to properly discuss the issues of the various kinds
of fsync, instead (it seems to me) just making a selection of vague comments.
That is a shame, as really properly understanding file integrity is a really
important issue, which is very easy to get very wrong.

When ext4 came out, I remember a large number of apps losing data, as the
metadata and 'normal data' caches can get out of order, meaning that:

Write file B. Rename B -> A.

Can result (after a crash) in A being empty, as the rename can occur before
the contents of B are actually written.

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Swannie
Agreed. These slides are like "Disks are not memory 101". I'd hope the talk
went into more details.

After an hour or so reading semi-related material I have an understanding that
goes beyond these basics :-/

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vimalg2
Converted the Presentation PPTX to PDF for accessibility:
[http://dl.dropbox.com/u/5137/pdf-
link/What%20Every%20Data%20...](http://dl.dropbox.com/u/5137/pdf-
link/What%20Every%20Data%20Programmer%20Needs%20to%20Know%20About%20Disks%20Presentation.pdf)

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ntoshev
Slide 6: "[Disk] throughput: 768 MB/sec on SATA 3" is misleading, consumer-
grade rotating disks barely fill SATA 1 with ~70 MB/sec. SSD are faster in raw
transfer, and if you have a RAID you are not limited by a single SATA channel
any more.

Slide 13: "Laugh at MongoDB" is pretty stupid, mongo makes certain trade-offs
that are not for everyone, but they are still meaningful.

The presentation doesn't explore the RAID options, which is a shame.

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mevodig
He's referring to the bus speed of SATA 3 as an upper bound -- but like you
mentioned, if you throw RAID and such into the mix, I'm not so sure either
that it's a very useful number.

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koopajah
Is there a video recorded of the presentation somewhere? This seemed really
interesting

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delta1
I was really hoping for a video, actually. Audio would suffice too :)

