[PROBLEM] External HDD periodicaly disconnected and reconnected as RO

[rikardo1979]

nice to see more home m8's here
I think there might be an HW issue as mk01 mentioned, so means the issue with powering. And I dont mean that it is just unsufficient but I mean that if I understood it right you have two PSUs, one feeding the USB device and other feeds the RPi. So as you are electrically connecting these two together through the USB device (PSU<>HDD<>RPi<>PSU) so actually this may cause the issue. I have personal experience as I was testing and USB drive with external PSU and when I connected this into my RPi with own PSU this failed to start until I have unplugged one of the PSU's either RPi or DVD one
Think about it and give it a shot