The question title is obviously not clear because I am not sure what is going on.
I have a 1TB external HDD. I've always been using it on my old laptop. On my new laptop running Ubuntu Gnome 16.04 I am trying to move some files to it. I tried the GUI and the cli (cp -r & rsync).
The problem is the HDD seems to stop responding. For example, rsync hangs. It fails with a read-only filesystem error. The first time I was copying the files I saw this error so I plugged it into my old laptop and change the permissions of all enclosed files to read/write for all.
When I force stop the transfer (Ctrl+C) the command still appears in htop with status D.
The processes cannot be killed with either a 15 or 9 signal. Also I cannot unmount the disk. It says one or more processes are keeping the volume busy.