Hello, it seems a bit strange because the CurrentDmesg.txt (comment #9) doesn't show the problem. Also I have Trusty Tahr installed and a WD USB3.0 external HDD and I haven't such problems. Either I connect it to USB2.0 or 3.0 port.
It would be helpful if you provide additional information during the connection of HDD. Open a terminal (CTRL+ALT+T) and write: watch -n1 "dmesg | tail -n 30" then connect the HDD and post back here the lines will be produced. Best Regards NikTh -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1254261 Title: xhci regression: usb 3.0 hdd disconnects immediately To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1254261/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs