I have a Dell's 1TB portable external hard drive(PDA1000B model). It mounts well and works well until I copy large number of files in a bulk, which should casually take a longer time.
The problem is, somewhere along the way it goes to sleep (or standby mode, I don't know what's the difference here.) after some time of starting write operation in it. The progress bar in the nautilus shows that copy process is slowing down. This follows computer starting to show glitch while moving around and doing virtually anything.
I found a question with a similar problem but didn't quite get what the solution was, even if it was I can see nothing that could resolve the power issues. But even with the same external HDD I had no such issues back when I had windows running in the computer.
Wish i could be more helpful with the details. Thanks in advance for any suggestions/solutions.