Powering multiple pi's and multiple external hdds

Question

I have looked around here and on other sites but don't really come to a clear solution on what to do specifically with my setup.

I'm searching for a way to power the following setup efficiently:

Basically:

1 Raspberry PI 1
1 Raspberry PI 3
3 Raspberry PI 3 B+
2 SEAGATE Expansion Portable (2015) 1TB
1 TOSHIBA Stor.E Canvio Basics black 1TB 2.5"
1 WD unknown 512GB
1 unknown 1TB

I didn't know that I need to power those HDD's externally when I bought them and now I'm therefore struggling to provide enough power for them.

I tried to connect a Y cable to a second port of the PI, which worked better for one of the drives, but it still failed when I wrote a lot of data on it.

So now I have the following ideas:

Buy 6 active power hubs USB 3.0 Power Hub, 4 USB Ports + 2.4A Charging Port, 15W(5V/3A) power adapter. Since this hub has a special port for charging, I thought it would be optimal for my problem. Attach them the following way:
Two Anker PowerPort (60W 6-Port USB Charging Hub) and a couple of USB Y cables. Connect them like this:

Is there a better way compared to those two, I want to reduce power adapter usage, don't want to use 12 since that seems a bit overkill? And if there is no better solution, which one should I use?

It is far from clear why you would want 5 Pi and 5 HDD, but given this overkill worrying about power seems trivial. — Milliways, Jun 21 '18 at 12:03
Because I want to. I had some hdds and pis lying around. Now I'm trying to self host ~20 programs and 3tb of multiple cloud storages instead of running everything on a big VPS. It's basically a self learning experiment on how to manage multiple servers and how to backup everything as well. It's all up and running, the pis work fine and all of their memory usage is at 90-100% and cpu is also nearly maxed. The only thing which happens sometimes is that the HDDs fail (hang) since they are under powered. — Lyze, Jun 21 '18 at 12:07
I know that I could have bought a bigger server with more power and intel cpu, but I didn't want to since I was curious how to manage multiple servers instead of one. And how to make everything modular, so that I can just add another and everything works instantly. That's basically my whole reason why I have that setup. — Lyze, Jun 21 '18 at 12:11
*"Since this hub has a special port for charging, I thought it would be optimal for my problem."* -> I'm dubious that charging hubs or adapters of any sort are ideal for **powering** electronics. Although often enough they may work, in my experience they have all failed at some point (e.g., with peripherals powered in turn by the pi) when an actual *power supplies* did not. Although some of the latter also aren't up to snuff, if you are going to drop some cash, your chances are better with dedicated supplies. — goldilocks, Jun 21 '18 at 12:23
@goldilocks I currently use normal raspberry pi power supplies ([something like this](https://www.amazon.de/iTrunk-Raspberry-Netzteil-Ladegerät-Mikro-USB-Kabel/dp/B01MDUSBPV/ref=sr_1_1?ie=UTF8&qid=1529583978&sr=8-1&keywords=raspberry+pi+strom)). Aren't those normally not good enough? And how would I power then the hdds properly? — Lyze, Jun 21 '18 at 12:27
Yes, that's what I mean by "power supply". Although again, some of them are better than others and a good charger may be better than a bad supply. You might be best off to buy one and see how it fairs. If you are buying supplies then hopefully the HD's will work off the pi -- or you could use a powered hub for them, since they are more to spec WRT USB power (they don't draw as much as a Pi can). — goldilocks, Jun 21 '18 at 12:33
Yep, I have those on every pi right now. Some of the hdds require more power though sometimes and die. If I'd buy now active USB Hubs for the HDDs alone then I'd need a total of 12 power supplies, which isn't really great. That's why my question was if I could power the pi from the same hub's charging port instead to reduce the amount of power supplies back to 6. — Lyze, Jun 21 '18 at 12:43

score 0 · Answer 1 · answered Jun 21 '18 at 15:11

You are creating a wiring medusa of power. :D Let's chop that complexity down a bit.

Since you are building your own datacenter, consider datacenter solutions. For example multiple computers are rack or blade mounted in a datacenter. Similar solutions exist for the Raspberry Pi. We do not endorse individual vendors, but you can easily find such solutions yourself.

You should also consider RAID drives

score 0 · Accepted Answer · answered Jun 22 '18 at 01:27

You have asked a couple of shopping questions, but most of these are inappropriate.

If you want to power 5 Pi in a frame DON'T use 5 PSU. It is cheaper, and more reliable to use a single PSU. In fact, this is what most Pi clusters use.

I use one of the 5V switch mode PSU designed to run LED light strips - these are well regulated. Choose one with a suitable current rating - 12A would seem appropriate for the layout you specified.

You COULD use 5 USB cables, but most such applications power through the 5V pins on the Expansion header - this makes it easy to use decent sized cables. See Raspberry Pi Power Limitations for further information.

The self powered HDD are probably not the best choice, but as you have them you could try powering from the Pi. Whether this works reliably depends partly on the HDD - some of mine work, others don't - I normally use a powered hub, but 5 hubs would be clumsy.

You could either use Y-cables or make a custom cable to 5V power and isolate from the Pi 5V. All the drives can be powered from the same PSU.

score 0 · Answer 3 · answered Jun 22 '18 at 12:10

RPi 3 should be able to power a hard disk attached to it, provided it receives enough power itself. HDD plugged into RPi 1 should probably be powered by a Y-cable or be self-powered.

In total, each RPi would consume about 1A, and so would each HDD. If I were you, I'd buy a single 5V / 10A power supply and use it to power all the RPis and the HDD you plan to plug in the RPi 1. Instead of USB hubs, you could simply buy DIY USB connectors and make your own power cables for the RPis. Alternatively, you could power the RPis via the pin header.

HDDs could be attached to RPi 3 by regular USB cables, provided you pick cables which are thick and short, so that they can carry the necessary current.

Powering multiple pi's and multiple external hdds

3 Answers3