DVR hard drive and another

1) The disk doesn't actually run all the time.  It runs at anytime the DVR needs it to record, playback or buffer (for Live trick-play functions like Pause/rewind/FF) or when processing schedule updates.  Note that when another STB is watching live TV, the DVR's hard drive is buffering for that other Set Top.  I hear mine spin up in the middle of the night, and then spin down a minute or so later.

2) The "lights", actually LEDs, have to flash all the time because they give you status information about what the RG is doing.  It can be very helpful for troubleshooting.  Since the RG doesn't know when it's having trouble and you need the status lights, and since you need to know what's a normal pattern and what's not a normal pattern, they have to run all the time.  However, these aren't very bright LEDs, and they don't take all that much power.  If you have a conventional nightlight anywhere in your home, it's burning more electricity than all the LEDs in your RG.  Which is why the newest thing in general lighting these days is LED based lights.  BTW, it's good that they're flashing green.  If they're flashing Red, well, that's not good.