[PROBLEM] External HDD periodicaly disconnected and reconnected as RO

[mk01]

You should be talking English as we are on international forum, Towdie!

Of course you can test it even on the windows. If it is not erratic there, HDD will be fine, just RPI does not have enough power to spare for other devices. It was stated many times, one should not attach ANY usb device directly to it's USB ports - to be on the safe side.

But this really looks like lack of power at some moments, where HDD disconnects from the bus, kernel catches those events, for safety tries to remount as RO and because it is still trying to connect, this slot (sda) stays internally busy, so when then HDD reconnects, it gets next free block device (sdb).