I have been having what seems like this issue with both LaCie and Seagate external drives when connected to USB 3 ports.
I just had connections to a server freeze and found this message when I went to the physical display (I can share a low quality image of the full screen if that helps): [309540.436290] BUG: unable to handle kernel NULL pointer dereference at 00000...0000f0 [309540.436313] IP: [<ffff...>] _raw_spin_lock_irq_save+0x1f/0x60 ... [309540.533342] Kernel panic - not syncing: Fatal exception in interrupt [309540.533366] Kernel Offset: 0x0 from 0xff[... hard to count characters] [309540.533389] drm_kms_helper: panic occurred, switching back to text console I have encountered the general issue of USB hard dive in USB 3 port freezing with three different devices running Ubuntu 14.04 over the last few months. The devices are: 1. a Dell laptop that came shipped with Windows that I installed Ubuntu on (not running very well, so I did not think anything of it) 2. a Dell Precision M3800 that came shipped with Ubuntu 14.04 - not sure exact revision when bug presented because I learned never to plug USB drives into USB 3 ports on the laptop, but today it has Ubuntu 14.04.3 LTS 3. just now, I caused a kernel panic on a Lenovo ThinkServer that has Ubuntu 14.04.2 LTS - at this point I thought I should log this. Additional version info is: Linux version 3.16.0-50-generic (buildd@lgw01-03) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #67~14.04.1-Ubuntu SMP Fri Oct 2 22:07:51 UTC 2015 (Ubuntu 3.16.0-50.67~14.04.1-generic 3.16.7-ckt16) Note: the symptom for #1 and #2 was that plugging a drive into a USB 3 port caused the computer to 'freeze' - not much useful Finally, things work fine with all three computers iff I am careful to use only the USB 2 ports with the LaCie or with the Seagate drives. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1242321 Title: USB 3.0 Harddrive not recognised To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1242321/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs