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Re: Rackmount cage

Mon Sep 26, 2011 8:59 am


So I have this idea...

I can see so many (non mission-critical) uses for Model B R-Pi units in a data centre that I want some way of shoving as many into a space as I can.

What I'm thinking of is a rackmount cage that R-Pi units can slide into... Something like this:

(please excuse terrible drawing and photograph!)

First hurdle - the R-Pi has sticky-outy bits (technical term) that mean it can't slide straight into a cage. So, there would have to be some sort of sleeve the R-Pi could clip into to give it straight edges.

Second hurdle - power. I think I'd put a Nanode ( into the cage which would (in conjunction with some relays) allow power to be cycled to each individual R-Pi. For niceness, a bi-colour LED shows the state of power to each device (on/off). On the basis that the release boards are similar in layout to the Alphas, power should be provided to the boards from the back of the cage - either fixed plugs, or a loose cable. Given the incredibly low power requirements, a smallish mains transformer should be able to power the entire cage and all the R-Pi units.

Third hurdle - Access to Ethernet port. Assuming that the layout of the release board is similar in layout to the Alphas and that power is provided from the back of the cage (see above), then the Ethernet port would be at the front of the cage. The cage would therefore need some (probably not very strong) retaining mechanism to ensure that cards aren't pulled out by the weight of any dangling Ethernet cables. A simple bar running the width of the cage would probably do.

Fourth hurdle - Storage. I'm thinking that my OS image would simply mount a remote NFS export, but I suppose that I could build space in to permit a drive to be attached to one of the R-Pi units in the cage...

I think that's about it.

Any thoughts?

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Re: Rackmount cage

Mon Sep 26, 2011 9:13 am

It has been suggested that I consider a top-loading style (a la This would certainly increase density although it would take it well beyond my requirements. There would also be the issue of routing the Ethernet cables. Food for thought though.

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Gert van Loo
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Re: Rackmount cage

Mon Sep 26, 2011 7:29 pm

If you use a normal Ethernet cable the plug 'clip' would prevent it from falling out.
Would you need a keyboard/mouse/screen or use remoter (Ethernet) login?

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Re: Rackmount cage

Tue Sep 27, 2011 7:50 am

I was more worried about the weight of the cable pulling the R-Pi out of the cage rather than the cable out of the socket.

I don't see there being any need for keyboard/mouse/screen - I think everything I need to do can be done remotely. Perhaps a serial console, but that would increase cost and complexity at this stage. The way I see it is that if I have a bank of, say, 15 to 20 R-PIs in a rack, I can afford for one or two to go down - it's simply cost-effective enough to have some as hot spares pending a visit to the DC to resolve the problem.

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Re: Rackmount cage

Tue Sep 27, 2011 10:01 am

Is there at least one side of the pi that has no connector ?

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Re: Rackmount cage

Tue Sep 27, 2011 12:04 pm

Nope, connectors on all four sides. Two sides have one connector each one is power the other is the double USB.
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Re: Rackmount cage

Fri Nov 25, 2011 2:40 pm

Your sketch reminds me of the API Lunchbox:

I can picture the sleeve in your drawing as a means to route all the inputs to one side of the Pi so that it could be plugged in to the back, simply by sliding it into the slot.

However, if access to all four sides is important, then maybe it'd be worth considering going vertical instead of horizontal, like this "Mini-Cluster":
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Re: Rackmount cage

Fri Nov 25, 2011 5:28 pm

depending on its intented use as cluster/rack setup the long side with the hdmi port is kind of free since you might not need it anyhow.
and the hdmi port will probably not stick out too much beyond the board.

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Re: Rackmount cage

Fri Nov 25, 2011 6:53 pm

You might get away with something like this:

To shift the HDMI 90 degrees. That would fit within the sleeve, and contribute to making that side less of an impact.

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