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?
If model B has the dual USB ports then yes it is model B. Yes I find this issue very odd as well... The only thing I can figure is that is must be the GUI is some way whether it is corrupt on the SD card or otherwise. Would be odd for it to be corrupted across all 5 cards however... Some people recommend daisy chaining the USB hubs together rather than utilizing both ports on the Pi but it doesnt seem to be an issue on startup so I dont see why that would cause a problem on a restart... Also not that this is related but I notice when I go to manually restart the machines that the GUI has completely locked up and sends me to a nearly blank html page that looks like an empty repository or the like. This will sometimes occur after a few minutes of mining and the GUI will not be available to me until a fresh hard boot of the Pi... The machines continue mining through this issue so I never really thought it was a huge problem but perhaps my intermittent ability to access the GUI is related to a corrupted image or a bad kernel?