Notice
I could not find the solution but after installing Ubuntu 16.04.2 LTS the problem no longer exists!
The Problem
I have a 1TB Transcend external hdd (inner chip is WDC_WD10JPVX-22JC3T0_WD-WX11A15R3AC8) and when I try to safely remove it either from file manager or even from command line with udisksctl unmount -b /dev/sdb1 and then udisksctl power-off -b /dev/sdb1, it immediately pops up again and won't power off.
I'm using Ubuntu 16.04.1 LTS.
- It happens either USB2 or USB3.
- It can safely be removed in either Mac or Windows!
- I tried 16.04 live and could not safely remove! but my HD can be safely removed in a live 16.04 booted in another PC, and also can be safely removed in my laptop in Windows!
These are some output after running udisksctl unmount -b /dev/sdb1 and then udisksctl power-off -b /dev/sdb: