

Getting Physical - Seagate Kinetic Drive Hardware - jarnold
http://swiftstack.com/blog/2013/11/01/seagate-kinetic-ethernet-drives/

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ambiate
RAID over IP via broadcast? From a security standpoint, it would seem there
are many hurdles to jump. Not too long ago, I talked to Dickinson about what
you guys do. I never considered the amount of harddrives necessary to
facilitate Swiftstack's goals. Of course the software challenges are
interesting, but the amount of hardware and maintaining risk/DR/costs/etc. Oh
man. Hats off to you guys.

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notmyname
It's not RAID over IP. Each drive itself is a network endpoint.

On the practical side, this means that the drive is "connected" to one or more
servers (and can be re-homed on the fly). The storage system itself is
responsible for coordinating the communication across the cluster of Kinetic
drives. In our case, the coordinating storage system is OpenStack Swift.

On the humorous side, this means that technobabble like "Can you ping the boot
record?" or "What does a traceroute to the directory show?" actually sorta
make sense now.

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ambiate
RAID over IP was a joke. I remember reading this story about someone flooding
routers to turn them into a broadcasts to view the flow of packets over the
network. I imagined the same thing, then said, hey with HDDs and broadcast,
you could simulate RAID. I made a long stretch on that one.

~~~
mbreese
That's probably not too far off. If you wanted to do mirror a write, you could
imagine broadcasting that same packet to a set of devices. The devices would
have to figure out whether or not they needed to store the packet. Otherwise,
you'd be sending N packets to the same switch for N-way mirroring. In a
typical hardware RAID, the sector write is sent to the RAID controller once.

It's probably not too long of a stretch.

~~~
toomuchtodo
Writing with multicast and using tcp only for the control plane? Interesting
concept.

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mrbill
Same connector as SAS, but a different pinout?

Does this not scream "bad idea" to anyone else?

~~~
jarnold
This is a good thing for a couple of reasons. First it allows equipment
manufacturers to build chassis with the same drive trays that are already in
production. Second, it that from a drive assembly standpoint, the same build
and testing equipment can be used. This should speed development and
manufacturing quality.

Is the concern more from an ergonomic perspective, that someone in a data
center may plug in a drive into the wrong system?

~~~
mbreese
If the testing equipment is expecting a SAS port, then wouldn't the dual
ethernet ports pose a problem? Or, is it that they are using SAS power pins to
do the ethernet transfer leaving the other pins untouched? (I don't know my
SAS pin-outs very well).

The main concern would be that, yes, someone could plug the drive into the
wrong system.

