How to safely shut down ES1640dc/ES1640dc v2 NAS and unplug the controllers?
In the ES1640dc and ES1640dc v2 dual-controller NAS devices there is a Battery Backup Unit (BBU) installed for each controller. It is used for flushing of data in the write cache onto the mSATA when the system loses power unexpectedly. This process is called C2F(Copy-to-Flash).
Normally we would shut down the NAS from the web GUI but sometimes you may encounter system hangs where this is not possible and you need to unplug both power cords to shut down the device. Right as the cables are unplugged the C2F process will start. The system will be powered off completely but you will still see an orange LED and the LED of BBU indicating the C2F is in progress. This process generally takes one to five minutes.
Note: DO NOT unplug the BBU or controller until both LEDs are off on each side.
The system is now completely shut down and it’s safe to unplug the controllers.
