cooper Posted March 25, 2014 Share Posted March 25, 2014 Long story short.... ... got bored with a LOT of things this year, so half januari I ditched the girlie and as luck would have it a former co-worker positively mentioned my name to the recruiter if his current company. I had an interview with them yesterday and I went in somewhat cocky, feeling that I knew my stuff and was good at what I do only to find out during that interview that over the last 6 years I've effectively fallen asleep at my work desk and since I also effectively stopped tinkering and hacking during this time I've actually been standing still resulting in the technological advances flying past me without me even so much as noticing. During the interview certain projects, products and concepts were mentioned that I wasn't familiar with and I spent (way, way too) much of last night diving in with the ferocity of a starving hyena at a captured gnu. (Maybe I should add that even though the interview itself was humbling for me, I did get a callback and we're currently discussing salary) I'm very much aware I'm playing catch-up but very happy this company jolted my synapses and am once again actively scouring the internet looking for everything I've missed so far. And in the course of that... ... I'm looking into the concept of HA and HP clusters. And an easy and by far cheapest way to dabble with this is using a couple Raspberry Pi. Case in point, the 64 node supercomputer at the University of Southampton. Looking at that link and in partucular the pictures at the bottom, I got inspired. So my plan is to (first) get 4 Pi's and play with them, see how that goes and if I like it expand upon that if I feel like doing so. You see in one of the images how they're powering every single Pi there with its own wall-wart. That struck me as rather ugly. All those plugs, all those cables. Since the device is powerd over its micro USB port, my first idea/solution to that was to use a powered hub to feed them. Problem is that powered hubs that adhere to the official standard won't supply more than 0.5A per port and the Pi officially requires 1-1.2A. There's a list describing powered USB hubs that a single Pi can run off of, by the general idea that the Pi can use up more amps if the other ports remain vacant or are filled with low-power devices. In my case that won't suffice since if I were to go this route I'd want to get a 4-port hub and connect all 4 Pis to that one hub rather than use a 7-port hub to connect them, just to have sufficient power available. So I'm now thinking about taking an external power supply/brick I have lying around to power the PicuPSU in a now-dead (capacitor plague) Via Eden Mini-ITX. It's currently set to 12V but there's a little plug you stick into it to change the output voltage and if I didn't toss the alternate plugs (please, please, please) I should be able to switch it to 5v and deliver up to 10 amps (it's rated at 60W) to a power rail. Using some wire, solder and micro USB connector plugs I can wire the lot up from a single power brick. Should be a simple little hack. With it the full cluster, even when expanded to 7 or 8(*) Pi's, should be able to run off this one power brick, greatly reducing the cable clutter and possibly even raising electrical efficiency. Does this plan sound sensible to you, or is this more an elaborate way to fill my home with the Magic Smoke? * I'm thinking that the cluster is on its separate network segment using a standard 8-port switch. One of those ports connects the cluster to the main network so I can attach Pi's to the remainder, making a total of 7 Pi's the logical amount. From that I could make one a load-balancer and the other 6 worker nodes. Alternative would be a USB network adapter on the main node / loadbalancer to tie into the main network and all Pi's on the switch which is now dedicated to the cluster... We'll see. Quote Link to comment Share on other sites More sharing options...
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