RaspPI4 wont start if USB hub with 8 disc is connected

Chia Farming & Harvesting
1

Hello,
For farming i am using Raspi4 with Ubunto desktop 64bit.
It is powered with 5v, 3A power adaptor.
I have a not powered USB hub (model ORICO 7 Ports transperant usb 3.0) with in tot 8 external hard drives connected to.
All external hard drives are with their own power supply. And some of they have also their own integrated usb hub. In that way i have connected some of the discs.

The problem is that when i restart the PI from the power, it wont fire up. The only way to fire up is to disconnect the usb hub.
After it is booted, i can connect the hub and all works fine.

Please advice how to solve this problem, as my PI is installed on a remote location and is hard to ask someone to unplug/plug th hub. ?

Thanks, Chris

2

I can’t understand your post. If you are using a single 7 ports USB hub, how can you connect to 8 external HDDs?

Edit: I understand now. It seems you are using the external HDDs that come with a USB hub. This is not a good idea as you’re wasting your device slots (in the controller host) for no good reason.

You can try fixing the issue by putting the eighth drive on an empty port which is not connected to the hub.

3

There are some technical problems because the power supply is not uniform. The device may not detect that the host has been restarted

You can try to add a usbreset command in the startup script, it may work

4

Because the external discs have also their own usb ports, acting as a second hub behind the main one.

5

I understand now. It seems you are using the external HDDs that come with a USB hub. This is not a good idea as you’re wasting your device slots (in the controller host) for no good reason.

You can try fixing the issue by putting the eighth drive on an empty port which is not connected to the hub.

6

Hello,
Tried this. It is not working.

btw, when you say that with such a disc with integrated hub i am wasting my slots, is that mean that if i bye 8 discs, each with 2 additional usb, they will count as 3 per disc and total will become 24 slots in the controller host ?
As i know, thats above the RPI4 limit of 20 slots. So this mean my 8th disc will have problems and will start to randomly disconnect, right ?

7

Yes, the controller host has limited device slots in which the hub’s also counted as device(s). However, as far as I know, the Pi should support 30 devices. You can see my post here.

8

Hi, yes but it do not load the OS so the starup script can start.
Any idea?

9

I think I understand you said, this problem is cause by your usb hub.

your hub don’t have a Reverse current protection,
the external power supply will reverse the current to the PI when the PI main power down, resulting in failure to start or other problems. You can try it when there without external power supply. It should be work normal,
you need a usb hub with Reverse current protection

Although some cheap hubs are marked with yes, they do not. If you know how to test, you can test whether there is countercurrent protection

10

Thanks a lot for you answer.
But my hub is not powered. Is it possible this current to come from the external drives power supply?

11

External power supply refers to all power supplies connected to the USB port topology chain except PI power supply itself

External disk power is included, you can test it without external power supply and try a usb hub with countercurrent protection function

12

Ok, i see.

Can i have some links from amazon for such hubs with Reverse current protection?
Isnt it possible just to add some simple usb back current filter and to use any usb hub ?

13

As it Involving high-frequency circuit and high-speed data transmission, it can not be simply filtered.
Sorry,I don’t have these links, you can ask somebody who are using these type of usb devices or ask the seller to confirm

14

Hello,
I found this one:

It is written it has reverse current protection.

15

Hello,
I have found workaround.
I just removed the hub and pugged it in one of the external discs usb ports, and then i plugged this disc in the RPi. I suppose the external discs have some reverse current protection, because the problem was solved.
Anyway, i will update here when i get the VKUSRA USB Hub also.