which I think to be pretty decent quality hubs. The ones I got shipped when I bought the units were trash 6 dollar hubs from china. Not a single one of them worked properly. I wasn't even able to boot a pi with 20 units. Since I bought these hubs everything boots up and runs fine its just a matter of working out the shutdown issue. Can I work around this problem by maybe entering a large number like 500 for an 'n' value of time between restarts on the GUI? As I mentioned the issue seems only to occur when the GUI sends the command to restart. A hard reboot works fine and they come right back up and start hashing.. Also would there be anyway to program the pi to hard reboot the machine every set amount of time? Thanks for the help!
If you think the restart is causing the hanging, you can set this to 0, which means, it will never restart the mining process. But still, It's strange, It should run fine with 20 miners. I am using a different hub though. What model PI are you using ? the model B?