Rules of Thumb for Disk Power Management

[nello]

There appear to be two parameters to control disk drive power consumption, both of which are on the screen:

Storage > View Disks > (Select a disk and) Edit

They are:

1. HDD Standby
2. Advanced Power Management

Are there others?

My storage consists of six WD Red 3TB drives configured as a single RAIDZ2 Volume.

What are the appropriate (range of) values to set these parameters for a home, FreeNAS installation running the following in Jails:

• CrashPlan (Destination for 5 computers)
• MythTV
• Plex Media Server
• OpenVPN

Thank you.

- nello

 

[Mirfster]

There are different thoughts on that; but from what I have seen most lean towards NOT having the drives spin-down. The thought on this is that it actually causes more wear on the drives.

My 2 cents..

 

[nello]

There are different thoughts on that; but from what I have seen most lean towards NOT having the drives spin-down. The thought on this is that it actually causes more wear on the drives.

Is this how I keep them from spinning down:

• HDD Standby
  Always On
  
  
• Advanced Power Management
  Seems like Level 128 or above keeps the drive spinning; Is there a reason to go higher?

Do I have to change each drive individually, or is there a way to change them all at once to the new settings?

Thank you.

- nello

 

[Mirfster]

I believe you would have to do each one. TBH, I leave all of mine at the default. Of course I have not been running mine for years (yet) like others. Perhaps one of the more experienced members will chime in.

In the meantime, here is an interesting thread that you may want to see in regards to Power Saving:
https://forums.freenas.org/index.php?threads/save-power.40364/#post-256812

 

[DrKK]

I turn all that shit off. These drives (WD reds) are like 1W when spinning idle. The numerical cash amount of wear and tear on the drive to spin it down exceeds the cost of the electricity to keep them spinning. It's really a no-brainer to me. At $0.10/kWh, leaving your drive spinning, is like, 100 hours = $0.01 in most part of the world. So if you have five drives, not even accounting for the times your drives would be spun up anyway, it's pure simple mathematics that the max you can even dream of saving is like $0.30-$0.40 (per month), ***TOTAL***, not per drive, for the whole NAS, by spinning them down.

APM off, spindown off, always on, etc. etc. is what I would recommmend.

Spinning down your drives is for suckers, just like GELI encryption of the pool is for suckers.

 

[nello]

… turn all that shit off.

Done.

 

[ovizii]

I turn all that shit off. These drives (WD reds) are like 1W when spinning idle.

yes, but will they ever be spinning idly when the (I think I remember this is how it works) syslog is being written to the main pool?

 

[DrKK]

yes, but will they ever be spinning idly when the (I think I remember this is how it works) syslog is being written to the main pool?

This is actually a million dollar question. As you suggest, even when people desperately try to spin down their drives, they find it's nearly impossible, because of things like syslog or other perfectly legitimate FreeNAS activity.

Bottom line: spinning down drives is a solution to a non-existing problem; the expected value of cost of wear and tear to your drive exceeds the pennies you'll save on electricity; and it probably won't work anyway because of how FreeNAS operates.

 

[Ringerl]

From what I've read it's more like 2-5watts for modern hdds in idle state:
https://www.wdc.com/content/dam/wdc/website/downloadable_assets/eng/spec_data_sheet/2879-800002.pdf