TRUENAS Hardisk Standby

Hi Folks
One drawback i underestimated on reusing an old PC for Truenas, was its power consumption. I am trying various things to reduce idle power consumption. One thing i wanted to look at was putting the HDD in standby mode when not in use. But found some articles that have some caveats ( Disk Standby ). Before i go ahead and do this some queries as i have seen opposing views on putting disks on standby

  • is it worth putting the disks on standby (from a power saving perspective). I have a NAS with 8 HDD.
  • How often should the auto SMART tests be conducted, would once a days suffice? as this is one of the things that wakes up the disks.
  • Another thing about putting disk on standby was to move to the system dataset and syslog to the boot disk (not preferred if boot disk is USB) instead of the data volume.
  • Does putting disks on standby reduce the life of the disk. Read that frequent spin ups and spin down reduce the overall life of the disk. Enterprise drives are manufactured to run 24X7.
  • Is there anything else i can do to reduce idle power consumption ?

If you’re trying to save power as a cost savings measure, then you should also consider that wearing out a disk prematurely means paying more money for disks because you have to replace sooner. If you’re doing it out of an environmental concern, you’re still better off trying to prolong the lives of the disks as the carbon emissions from their manufacture while outweigh whatever emissions you save from spinning down your disks.

That said, this is entirely dependent on the question “does spinning disks up and down shorten their lifespan?” The answer is generally yes, but there are certain rare scenarios where that might not be true.

If this data is only accessed once in a blue moon or so, then it might make sense to spin down the disks in that time. But this is probably not your use case.

And regardless, any power savings you would get would be minimal. You’re better off trying to figure out a way to better cool the system if you want to save on power.

Assuming spinning disks, going to an SSD would save power/heat but certainly not cost (especially if you are using big drives).

Thanks for the response folks. The aim of power reduction is two fold
1 - Cost - Any reduction in running cost helps
2 - UPS - My UPS is 1000KVA unit and i am stretching it to its limit.

SSD too expensive… and also my understanding is that SSD fail immediately and totally unlike hard disks which usually fail gradually.

What I have done is to have two pools of disks. One for media content and downloading, which will never spin down because they will get accessed at random times all throughout the day and night. And another pool of disks for backup from mobile phones, laptops and such, which will only run at certain times because I have configured all the devices to sync and backup at certain times, i.e at night. I have no idea how much wattage it saves me, as I have yet to put a kill-a-watt in the socket. Some say it’s miliwatts, others that it is in the order of 10 watts per disk. I don’t know, guess I’ll find out.

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Wow, that is a big UPS :wink: . Sorry, couldn’t resist the 1000 KVA …

Oopps… Typo …Happens to the best of us :grinning: . Though a 1000KVA UPS at home would be a dream come true (if it was compact enough to fit in a home)