My external hard drive (Seagate 2 TB) keeps disconnecting momentarily and reconnecting. Since it causes nautilus to open each time it reconnects, leaving my computer on overnight has caused system crashes and I have to do a hard reset. I know I should shut off my computer overnight, but sometimes I forget, and I just can't imagine regular hard resets being good for my computer.
It's a new problem, and didn't used to happen, so I'm not sure why it started. It also occurs less when I'm active on my computer. If I'm writing a paper, it rarely occurs, but if I'm watching a movie, it happens relatively often.
I dual boot Ubuntu 15.04 and Windows 7. Cinnamon is me DE, but I sometimes use i3wm.
In Windows 7, my USB 3.0 has stopped working, and I wonder if that's related.
sudo -s
then run this script:while true ; do sleep 1 ; dd if=/dev/sdb iflag=direct count=1 of=/dev/null ; done
. Assuming /dev/sdb is your external drive, this will force access to it once every second until you hit ctrl-c. Leave this going for a while and see if the constant activity stops the disconnects.