HDD Load Cycles, Spindown and disk access

[IceBoosteR]

Hello Community,
I have my FreeNAS system for a while now, and i am wondering a little bit about the hdd access and spindown for them. I also have a question for the load cyle count.
First of all, I have 4 WD Red with 4TB, SMART attributes are looking like this:

Code:

D# ATTRIBUTE_NAME		  FLAG	 VALUE WORST THRESH TYPE	  UPDATED  WHEN_FAILED RAW_VALUE									
  1 Raw_Read_Error_Rate	 0x002f   200   200   051	Pre-fail  Always	   -	   0											
  3 Spin_Up_Time			0x0027   177   177   021	Pre-fail  Always	   -	   8108										
  4 Start_Stop_Count		0x0032   100   100   000	Old_age   Always	   -	   35										  
  5 Reallocated_Sector_Ct   0x0033   200   200   140	Pre-fail  Always	   -	   0											
  7 Seek_Error_Rate		 0x002e   200   200   000	Old_age   Always	   -	   0											
  9 Power_On_Hours		  0x0032   100   100   000	Old_age   Always	   -	   347										
10 Spin_Retry_Count		0x0032   100   253   000	Old_age   Always	   -	   0											
11 Calibration_Retry_Count 0x0032   100   253   000	Old_age   Always	   -	   0											
12 Power_Cycle_Count	   0x0032   100   100   000	Old_age   Always	   -	   35										  
192 Power-Off_Retract_Count 0x0032   200   200   000	Old_age   Always	   -	   1											
193 Load_Cycle_Count		0x0032   200   200   000	Old_age   Always	   -	   459										
194 Temperature_Celsius	 0x0022   127   112   000	Old_age   Always	   -	   25										  
196 Reallocated_Event_Count 0x0032   200   200   000	Old_age   Always	   -	   0											
197 Current_Pending_Sector  0x0032   200   200   000	Old_age   Always	   -	   0											
198 Offline_Uncorrectable   0x0030   100   253   000	Old_age   Offline	  -	   0											
199 UDMA_CRC_Error_Count	0x0032   200   200   000	Old_age   Always	   -	   0											
200 Multi_Zone_Error_Rate   0x0008   200   200   000	Old_age   Offline	  -	   0											

I personally think, SMART looks okey, 350 hours to 460 load cycles. But when my NAS is in IDLE (at night) and is defenetly doing nothing (I have all my jails down and the System Dataset is set to "freenas-boot" instead of my ZFS-data-pool), and I sometimes hear random disk access. I mean, you can hear when the drive is reading or writing somethin, and I randomly hear that, for maybe half a second. How can that be?
I have only SMART and SMB activated as services.

Keeping this in mind, I come to my next question, the hdd spindown. I need your help here. My system currently consumes about 50 watts for idling around, because my disks are always on. As I do access my NAS often at the weekends, and not in the week, I want to spindown my drives for the time, so save energy and increase the lifetime of the disks. I dont want that the drives will then spindown every 60 minutes, and spinup a few seconds later of no reason. Is there a preferred method to accomplish this? Or do you mean: Dude this are only 15 watt. Dont let them spin down...
I have read a lot of threads regarding this little problem, but don't have a conclusing for me. Maybe you can help here.

Greetz
IceBoosteR

 

[BigDave]

Please know that YMMV on this issue, but here's my thinking on the issue of spin down options.
1) NAS drives are designed and engineered to stay spinning, unlike desktop drives. Why spend the money
for them if you do not intend to use them for that purpose?
2) testing has shown that they last longer if they don't spin down.
3) power saved (and here's where it gets controversial) by the spin down, will in the end be spent on drive
replacement due to excessive wear from starting and stopping them.
4) saving power is important you say, but what about the energy used to manufacture the replacement drives,
would that end up being worse/same/better???
Hard drives (for the most part) are made in China, those factories produce metric tons of harmful pollutants into
the Earth's atmosphere annually. If I can take steps to make my hard drives last longer by keeping them spinning,
and as a result, reduce the number of manufactured replacements, that goes further in my mind!
Let the flaming begin :p lol

 

[IceBoosteR]

Please know that YMMV on this issue, but here's my thinking on the issue of spin down options.
1) NAS drives are designed and engineered to stay spinning, unlike desktop drives. Why spend the money
for them if you do not intend to use them for that purpose?
2) testing has shown that they last longer if they don't spin down.
3) power saved (and here's where it gets controversial) by the spin down, will in the end be spent on drive
replacement due to excessive wear from starting and stopping them.
4) saving power is important you say, but what about the energy used to manufacture the replacement drives,
would that end up being worse/same/better???
Hard drives (for the most part) are made in China, those factories produce metric tons of harmful pollutants into
the Earth's atmosphere annually. If I can take steps to make my hard drives last longer by keeping them spinning,
and as a result, reduce the number of manufactured replacements, that goes further in my mind!
Let the flaming begin :p lol

1) Yes thats a good point xD
2+3) Then the point is clear; no spindown then
4) Ehehe thats a good pint. It's like driving a Tesla and get all of your energy from a coal power station.