My PC has been powered off for a week, when I returned home today, I lost all USB 3 use. After some trouble shooting I can get my portable drives mounted if I boot the PC with them plugged in the usb 3 port. I originally though this was an issue due to today's update, except that I tried the drives on the same PC using 16.04 and experienced the same issue. Is this a hardware issue? My bios is up to date (2016 version). Any ideas how to further troubleshoot or repair?
It could be GRUB-related, this video explanation and fix may help:
Your point about the BIOS being up to date might be a little more involved, see:
Did any of that help?
So I reviewed the video. Than did the check on the askubuntu site. All checked well. So before changing my grub, I tried again and my USB 3 port worked. If/when the problem returns, I will try the grub fix and report back.
So the problem did return. What I learned is the issue is with a particular PNY thumb drive. If I put it in the USB3 slot, I will get a mount failure "Can't read super block". And any other USB3 drive I plug in afterwards will not work until I reboot. I have another PNY thumb drive that works just fine in the USB3 slot. Now the odd part is the bad PNY thumb drive that use to work in USB3 slot, works just fine in the USB2 slots. I guess I need to reformat that thumb drive or get a new one.
BTW...I did make the Grub change suggested in the video, it made no difference.