SAS on a Rosewill drive cage

Hardware Enterprise Gear
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Hi all,

Recently I started eyeballing these seagate enterprise drives on ebay. They are 8TB 4kn SAS3 drives for roughly $110. I’m sure I’m taking a gamble on them but if they end up being alright I would like to begin adding them to my array.

I have a Rosewill RSV-L4412 which uses these hot swap bays and appears to support SAS drives. Users in the reviews area report success with SAS in these bays, however something that confuses me… they are sata on the back of the cage

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and yet on the internal backplane

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Looking more into this, they dont seem to be the only ones doing such a thing.

Supermicro has this backplane which appears to use SATA on one side and supports SAS

How is this possible and when did it start?

Ultimately I’d like to use my current rosewill case with a 9300-8i and sata breakout cables to my SAS capable backplane. I’m not sure its going to work, but I’m otherwise at a loss how other people appear to be using these cages in this way.

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I have at least answered the question of, will it work…

image

I am still left with the HOW.

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Could the backplane have a built in reverse-er? Like reverse breakout SFF8087->SATA cables? Saying that, how do reverse breakout cables themselves work? Must be more than just dropping some pins or something?

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Hmmm… I am also wondering exactly how it can support SAS drives… maybe you would have to still connect it to a SAS capable HBA via a breakout cable?

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I was under the impression that an SAS cable had physically more conductors for more signaling, but I never actually looked into this.

It seems as though there is some black magic happening where by signals are combined with power and then broken out again.

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you do indeed still need an SAS capable card.

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I thought the data part of the SAS connector was physically the same as the SATA data connector, they just run different protocols.

The power is probably provided from the Molex connectors.

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My understanding was the pins between what would otherwise be normal sata connectors had some data function, but I’m new to this so :man_shrugging: I had assumed this meant there was more to the standard than just the conductors involved with typical sata.

This seems illegal and I’m waiting for the authorities to come and shoot my dog server.

Also what @Trooper_ish said about forward and reverse breakout is now baking my noodle fully into a nice lasagna.

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Yes, they do, but they are optional. If they aren’t there, the drive can only do unidirectional data flow at one time AFAIK.

SFF-8482 pinout
https://pinoutguide.com/HD/SAS_connector_pinout.shtml

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I don’t know how it works, but I have a backplane with a SFF8087 connector, and I use a reverse breakout cable to connect the backplane to four SATA sockets on my motherboard.
Both SAS and SATA drives seem to work in it.
I have no idea how backplanes work, but might have something to do with channels or something?
There must be some smarts on them, even if they don’t have multipliers or whatever

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aaaaaah see I didnt know that.

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