Any point or benefit to spinning down disks?

[Sokonomi]

I have a pool of 6 disks that I use for a daily backup pool.
They only receive data at night, once a day, for id guess about 30 minutes tops.
With the current Energy prices in mind, would it be useful to spin these down until needed?

It's clear this would be a weigh-off between lifespan and power consumption,
but with a single kWh costing 80 eurocents these days, it makes me wonder.
In fact I might even be better off building a cold stored once-a-week backup server instead?
I'm just looking to prevent my NAS from sucking back too many energy bill euros,
and 'sleeping' some drives, to me, seems the most obvious option.

Any thoughts/advice?

 

[Davvo]

Make sure to do so the proper way, there are guides about that on this forum, otherwise you may just wear down the HDD motor.

There are surely benefits in addition to the power savings: less heat and less noise, as well as less wear of the components (excluding the motor).

 

[ChrisRJ]

I would look into the direction of tiered storage. Like a daily differential backup on SSD, and the weekly full backup on HDD. Or a variation of this, depending on the amount of change, absolute data volume, down-time window of applications (if applicable), etc.

In other words, find a way to reduce the number of times you need to wake up the HDDs. Doing so daily would be too often for my personal liking. But once a week or month is a different story ...

 

[winnielinnie]

but with a single kWh costing 80 eurocents these days, it makes me wonder.

Let's round up and assume each drive consumes 10 watts while spinning.

That is 0.01 kilowatts.

For six drives, this comes out to 0.06 kilowatts.

For one month (720 hours), nonstop 24/7 spinning, this consumes a total of 43 kilowatt hours, which is about 34 €‎.

In fact, on idle (spinning, but no I/O activity), you could be looking at 5 watts per drive. So about 17 €‎ per month.

---

I understand it's not cheap, but there's more context to it.

• I rounded up to 10 watts per drive. (Some drives, such as He-filled and 5400-RPM, use fewer watts, especially when "idle").
• It doesn't take into account the cost (and frustration) of replacing new drives that die earlier due to too much wear and tear ("start-stop").
• It doesn't take into account that this is not simply an "added" cost, since there is still an energy cost to doing daily backups.
• There are other appliances (small and large) in a typical home that easily overshadow the energy consumption of hard drives.
  • You can save more on your energy bill with small changes in other daily habits.

---

My own server, which has 4 NAS HDDs (always spinning), 2 SSDs, and 2 NVMes, uses 63 watts on idle, which includes everything (even the fans and CPU.)

---

I'm not downplaying your concerns, nor am I telling you what you should do. Just wanted to add more nuance and context.

 

[Morris]

Let's round up and assume each drive consumes 10 watts while spinning.

That is 0.01 kilowatts.

For six drives, this comes out to 0.06 kilowatts.

For one month (720 hours), nonstop 24/7 spinning, this consumes a total of 43 kilowatt hours, which is about 34 €‎.

In fact, on idle (spinning, but no I/O activity), you could be looking at 5 watts per drive. So about 17 €‎ per month.

---

I understand it's not cheap, but there's more context to it.

• I rounded up to 10 watts per drive. (Some drives, such as He-filled and 5400-RPM, use fewer watts, especially when "idle").
• It doesn't take into account the cost (and frustration) of replacing new drives that die earlier due to too much wear and tear ("start-stop").
• It doesn't take into account that this is not simply an "added" cost, since there is still an energy cost to doing daily backups.
• There are other appliances (small and large) in a typical home that easily overshadow the energy consumption of hard drives.
  • You can save more on your energy bill with small changes in other daily habits.

---

My own server, which has 4 NAS HDDs (always spinning), 2 SSDs, and 2 NVMes, uses 63 watts on idle, which includes everything (even the fans and CPU.)

---

I'm not downplaying your concerns, nor am I telling you what you should do. Just wanted to add more nuance and context.

Frankly, modern hard drives are designed to start and stop. This includes enterprise NAS drives.

Not everyone has a tiny array like yours yet even with a little one like yours, every savings adds up. You even state this. These savings also help make our planet a better place to live, particularly for the 75 percent of people living on the coast.

Idle power is about 1 w, not the you state. SSDs are a good idea as they do run on a bit less power

 

[winnielinnie]

Idle power is about 1 w, not the you state.

In fact, on idle (spinning, but no I/O activity), you could be looking at 5 watts per drive.

Spinning, but idle without any I/O operations. (Not fully spun down and suspended.)

These savings also help make our planet a better place to live, particularly for the 75 percent of people living on the coast.

But the way to save energy is not done in a vacuum. That's why I mentioned to the OP:

There are other appliances (small and large) in a typical home that easily overshadow the energy consumption of hard drives.

• You can save more on your energy bill with small changes in other daily habits.

Assuming that all six drives (which the OP states they're using six drives) use a combined 20 kilowatt hours per month by spinning their motors (without any I/O activity except for daily backups), then there are other areas in life where you can easily shave off 20 kilowatt hours of energy usage (and even much more) with other options. Especially with larger appliances, but even with small appliances too.

The added risks, inconveniences, and hidden costs of constantly starting-stopping the drive motors to save maybe 14 kilowatt hours per month might not be worth it, and in fact may cause more harm than good over time. (When instead someone can use 15 minutes less central HVAC per day and save just as much energy consumption.)

That's why it's more nuanced than simply "Sleep and wake your drives every day to save energy."

 

[Sokonomi]

Make sure to do so the proper way, there are guides about that on this forum, otherwise you may just wear down the HDD motor.

There are surely benefits in addition to the power savings: less heat and less noise, as well as less wear of the components (excluding the motor).

I did look into it a bit and saw people claiming that spin down only properly works when you disable S.M.A.R.T. because else something in TrueNAS will keep poking it awake. But that seems a bit odd and dangerous. Surely this isn't necessary?

I would look into the direction of tiered storage. Like a daily differential backup on SSD, and the weekly full backup on HDD. Or a variation of this, depending on the amount of change, absolute data volume, down-time window of applications (if applicable), etc.

In other words, find a way to reduce the number of times you need to wake up the HDDs. Doing so daily would be too often for my personal liking. But once a week or month is a different story ...

I've been sorta doing this by letting my office computer run Cobian Reflector every morning as somewhat hokey semi-offsite incremental backup. Its a bit crap and I can probably do better. ;) I like the tiered storage idea, sticking in a cheap SSD to pull incremental backups every night and dumping them out every weekend is a good starting point Id think.

Let's round up and assume each drive consumes 10 watts while spinning.

That is 0.01 kilowatts.

For six drives, this comes out to 0.06 kilowatts.

For one month (720 hours), nonstop 24/7 spinning, this consumes a total of 43 kilowatt hours, which is about 34 €‎.

In fact, on idle (spinning, but no I/O activity), you could be looking at 5 watts per drive. So about 17 €‎ per month.

---

I understand it's not cheap, but there's more context to it.

• I rounded up to 10 watts per drive. (Some drives, such as He-filled and 5400-RPM, use fewer watts, especially when "idle").
• It doesn't take into account the cost (and frustration) of replacing new drives that die earlier due to too much wear and tear ("start-stop").
• It doesn't take into account that this is not simply an "added" cost, since there is still an energy cost to doing daily backups.
• There are other appliances (small and large) in a typical home that easily overshadow the energy consumption of hard drives.
  • You can save more on your energy bill with small changes in other daily habits.

---

My own server, which has 4 NAS HDDs (always spinning), 2 SSDs, and 2 NVMes, uses 63 watts on idle, which includes everything (even the fans and CPU.)

---

I'm not downplaying your concerns, nor am I telling you what you should do. Just wanted to add more nuance and context.

10 watts per drive seems a bit optimistic, at least in comparison with the build speccing guides i've used on this forum, where they say to mark down 35 watts per added drive. Or is that power draw only that high when they spin up? I unfortunately do not have the fancy gear needed to get snapshot power consumption readings.

My NAS has a 6 disk WD red pro main array that gets poked pretty much 24/7 so ill leave that spinning. Then theres a second 2 disk WD purple array for surveillance that definitely needs to spin 24/7. Third array is a set of 6 'retired' WD reds, these are the ones Id like to keep as a backup pool. I have a few more drives but I cant really think of a use for those so ill just keep using those as off site cold storage. Long story short; I have 8 spinners and 6 that could do with shutting off for a few days at a time, especially if I get an SSD involved as an intermediary daily backup.

Is it perhaps an idea to maybe build a cheap and basic 1U cold backup box? It would only have to come online to grab its data off the main NAS' SSD backup, then power off again. They typically hold only 4 drives, but that should still be plenty of space for the files I want backed up. I could just keep the remaining 2 as cold spares. Or would the cost of building and running this be too much to be really worth it?

 

[joeschmuck]

Is it perhaps an idea to maybe build a cheap and basic 1U cold backup box? It would only have to come online to grab its data off the main NAS' SSD backup, then power off again. They typically hold only 4 drives, but that should still be plenty of space for the files I want backed up. I could just keep the remaining 2 as cold spares. Or would the cost of building and running this be too much to be really worth it?

So I guess after reading this part it sounds like power consumption is not a factor? A new TrueNAS system (CPU, Motherboard, Power Supply, Fans, etc...) eat energy. If the 6 old drives were attached to a TrueNAS system that you already operate with other spinning drives then that would make sense. Unless you plan to power off the server when not in use.

I think the original question has been answered. You just need to figure out if you want to have the drives spin down or not, and you should be monitoring the spinup counter to make sure it's working as you planned. If you find out the drives are spinning up 4 times a day, that is not good.

Think about the long game, if you really want/need a backup server that sips power, you need to go with SSD media and a light computer to support it. There are many ways you could go about building a solution but we can only provide you some suggestions and then it's up to you. Budget is always a factor. So think about how much it would cost to replace those six drives with SSD's. Now how much electricity would that same amount of money purchase? Could you wait another 2 to 3 years until the HDD's started to fail and then purchase new cheaper SSD's to replace them? When I purchased my first 2TB HDD's they were the same cost as what a 4TB SSD costs now. Crazy! Let's hope that trend continues because I'd love to purchase three 6TB SSD's (in a mirror setup) in another year to replace my four 6TB HDD's (in a RAIDZ2 setup). The day will come.

Think the long game.

 

[Morris]

I did look into it a bit and saw people claiming that spin down only properly works when you disable S.M.A.R.T. because else something in TrueNAS will keep poking it awake. But that seems a bit odd and dangerous. Surely this isn't necessary?


I've been sorta doing this by letting my office computer run Cobian Reflector every morning as somewhat hokey semi-offsite incremental backup. Its a bit crap and I can probably do better. ;) I like the tiered storage idea, sticking in a cheap SSD to pull incremental backups every night and dumping them out every weekend is a good starting point Id think.



10 watts per drive seems a bit optimistic, at least in comparison with the build speccing guides i've used on this forum, where they say to mark down 35 watts per added drive. Or is that power draw only that high when they spin up? I unfortunately do not have the fancy gear needed to get snapshot power consumption readings.

My NAS has a 6 disk WD red pro main array that gets poked pretty much 24/7 so ill leave that spinning. Then theres a second 2 disk WD purple array for surveillance that definitely needs to spin 24/7. Third array is a set of 6 'retired' WD reds, these are the ones Id like to keep as a backup pool. I have a few more drives but I cant really think of a use for those so ill just keep using those as off site cold storage. Long story short; I have 8 spinners and 6 that could do with shutting off for a few days at a time, especially if I get an SSD involved as an intermediary daily backup.

Is it perhaps an idea to maybe build a cheap and basic 1U cold backup box? It would only have to come online to grab its data off the main NAS' SSD backup, then power off again. They typically hold only 4 drives, but that should still be plenty of space for the files I want backed up. I could just keep the remaining 2 as cold spares. Or would the cost of building and running this be too much to be really worth it?

Please show statics for modern drives failing due to spin down. We used to see stiction problems. There long gone. Where dose this 4 times a day spin up is bad come from?

If one is looking to save energy, one should do everything possible. One also needs to balance performance and power consumption and make the correct decisions for there applications.

 

[ChrisRJ]

What is the data volume we are talking about? Or did I overlook that?

 

[ChrisRJ]

Please show statics for modern drives failing due to spin down.

Well, if you question conventional wisdom and experience, why don't you provide statistics for your claim?

As to you saying that enterprise drives are made for frequent spin-down/up, I distinctly remember that in summer of 2020 Synology stated this was not supported with Seagate Exos drives. So it would be interesting what your source is on that.

I don't mean to be "aggressive", but vendors have made too many claims in the past that simply did not hold true. Therefore I meet your points with some level of skepticism. Please feel free to prove me wrong.

 

[joeschmuck]

Please show statics for modern drives failing due to spin down. We used to see stiction problems.

Stiction, funny word and if I recall correctly you are talking about when the heads get stuck to the platter. Yes, that is very long gone, I don't even have a hard drive around anymore where the heads rested on the platters. This would cause all kinds of issues, the heads stick and thus the drive motor would not spinup, or the heads when they got unstuck would take bits of the platter with them, not good either. Or the heads would bend slightly and now not be at the correct angle to fly over the platters at the proper distance. But yes, that problem has been gone for decades.

From my experiences: As for drives failing due to spin down, well that isn't the issue, it's when power is applied to the spindle motor that it causes a significant power surge to spin up. This surge generally does not damage the spindle motor but rather the drive motor electronics. The electronics are designed to last the warranty period. If they last longer then great for the end user, but once they fail then the end user buys a replacement drive which is great for the manufacturer. I'm not saying that these things are engineered to fail at a particular time, but I am saying that they are not engineered to last much longer than the warranty period. Some will fail sooner, some will last longer. Also, some drives are designed to spin up a lot, an awful lot. Specifically laptop HDD's. But they have significantly lower mass as well, but if we were to assume we are talking about small laptop drives then I agree, spin those babies up and down all day long. Those are designed for that kind of operation, mainly to save on power consumption.

Do I have facts to back it all up, not really anymore, the last time I tried to debate this the other person blew off my references so I'm not digging those things up again, not worth the effort. This means that my statements above are not facts as they are my opinions based on my experience.

I'm perfectly fine with people having a difference of opinion. If someone, anyone has a different opinion then it's perfectly fine to state it but by all means please keep it civil. There is no need to belittle someone or make them or their system feel inferior. I have a 10TB system, I by far do not feel inferior at all. I feel I have the typical home system and it's just my opinion, and mine alone, but who needs more than 10TB for a home system unless you are running a business, but that is just my opinion. Others can disagree and I'm fine with it. Some people want 80TB systems for home use (mainly video content) and that is okay.

Facts: So people like to state something is a fact when it may or may not be a fact. If you do want to state a fact, please provide a reference and link this way you can make a good factual point, and if it's a controversial topic, if you can find more than one reference it would be nice to state it. Do not challenge someone else to come up with facts. If you do not have references to backup your "facts", then they are just "opinions", even if you believe they are facts.

People come to the forums looking for answers and we all share our experiences, good and bad in order to help one another.

Cheers!

 

[winnielinnie]

There is no need to belittle someone or make them or their system feel inferior. I have a 10TB system, I by far do not feel inferior at all.

Only 10 terabytes?! Just delete your account. There's no way to live with such utter embarrassment.

I'm not insecure about myself...

Some people want 80TB systems for home use

Because some of us are enthusiastic about downloading, storing, and torrenting totally legal Linux ISOs 24/7 over an encrypted VPN. That makes up about 97% of home users with massive NAS storage.

 

[Davvo]

My grand total is 3 TB, and right now I am using less than 1/3 of that amount.
Please don't delete my forum account.

 

[joeschmuck]

@winnielinnie How did you find that video of my wife and her best friend talking about me? Damn you made me laugh! Too funny. Thanks for the posting.

My grand total is 3 TB, and right now I am using less than 1/3 of that amount.

If I would drop some of my multiple backups of my computers, I might be able to get down to 3TB easily. It's one Desktop, three Laptops, and of course includes the original image of those as well just incase I need to restore those.

 

[Sokonomi]

It seems I have lit a fuse on a powderkeg, for which I am sorry.

My important data is less than 1Tb, but that's not the whole plan. I also have a 6Tb mirrored drive for my surveillance, and I figured it would be nice to extend my record range by offloading to a pool that turns on once a week. I just figured it would be a waste of power to have that pool spinning for days without a need.

I've dug up some power consumption info on it the 3Tb WD red drives I have as spares:

3TB: read/write 4.4W, idle 4.1W, standby/sleep .6W

If i'm reading this correct, it means the difference between spinning and stopped is 3.5W per drive.
And in a week its doing nothing for 167 hours and then has a 1 hour load.
With the magic of math that means leaving it spun up guzzles 4.1126 kWh a week,
and having them powered down while doing nothing guzzles 0.6056kWh a week.
And with the current going rate of 80 eurocents per kWh, that means a difference of 2,80 euros a week.

So in spinning down the disks I could save 145 euros annually.
Some would consider that significant enough, including me.

So I guess it all hinges on how much an HDD suffers from standing still, really..?

 

[Davvo]

As @joeschmuck wrote the issue is not "standing still" but awakening from sleep: if you do that too much the motor might die prematurely.
And yes, you kinda stepped on a hornets' nest (but it's not your fault).

 

[joeschmuck]

(but it's not your fault)

I concur.

With the magic of math that means leaving it spun up guzzles 4.1126 kWh a week

I agree with you and your math. If you let the 6 drives run, that means you use 4.144kWh each week which @ .80 euro/kW = 3.32 euro/week or $3.50 USD/week. Annually this is 172.40 euro or $182.00 USD. Keep in mind start up current is generally about 7-8 Watts so there will be a slight increase in power consumption each time you spin up the drives, but overall it's not very significant since it lasts probably a few seconds for each drive.

This is just my opinion alone and I'm not trying to force anything on you but this is a very minor amount of money in the big scheme of things. I spend at least $70 USD going out to eat each week for a single meal (that is depressing in itself), where I could just eat at home and spend $15 USD or less instead. My point is there are other ways you could offset this small amount of money if you really wanted to just to justify letting them run and while I understand that no one wants to give their money to a power company, it's just part of life. Another way to offset this long-term, a small solar power recharger for maybe your UPS. If your UPS normally runs off the battery (some do and generate power from this source) then this could be an actual saver in the long run. Unfortunately my current UPS does not work this way. Think outside the box and long term. I'm actually thinking about doing some small solar projects. I don't have a lot of money to invest but if I can recoup my investment in 3 to 5 years then I'm going to do that. A whole house solar solution would take me decades to recoup and I will likely not live that long. My largest expenses are Hot Water Heater and HVAC, in that order. I have reduced my consumption by altering my thermostat. The water heater, well they make a heat pump version and when I need to replace this one, the heat pump version will be installed which will save me a lot of money.

Other things you could consider are case fans, find out how much current they draw and maybe replace with better lower current model. A few amps makes a big difference (amps * volts = watts, or .1 amp * 12 VDC = 1.2 watts). Some cheap fans draw .6 amps (some more), the better ones pull about .15 amps. See what you have and see if you can make a difference. Maybe if you have a lot of case fans, you could remove one, keeping in mind proper airflow. It all adds up. Also, larger slow moving fans generally draw less current than a smaller high speed fan. I'm thinking slow 140mm vs high speed 80mm or 120mm fans. But you need to look at CFM as well. I run my case fans at 7VDC, this causes them to run slower and they actually draw less power, make less noise, but air is flowing across the components properly.

Sorry for all the crap above, just trying to give you ideas that you may try or just to make you think of other possibilities.

With all that said, I do not pay nearly what you do for electrical power, I think I'm paying about 0.16 USD per kW (.15 euro), a significant difference. So I'm not in your shoes and I cannot judge you or your actions.

Sometimes it's nice to quantify how much our hobbies and other things cost us. We need to figure out if we can live with them.

If you do decide to sleep the drives, absolutely look at the SMART data to check the Start_Stop_Cycle value. Ensure it only increments as many times as you think the drive(s) should be spinning up. Often people overlook this and the drives spins up regardless. Sometimes it's because an external device polls the drive for some information, could be just a status and nothing significant. It does happen and sometimes you can't get away from it, not easily at least.

Best of luck to you.

 

[VulcanRidr]

I have a pool of 6 disks that I use for a daily backup pool.
They only receive data at night, once a day, for id guess about 30 minutes tops.
With the current Energy prices in mind, would it be useful to spin these down until needed?

It's clear this would be a weigh-off between lifespan and power consumption,
but with a single kWh costing 80 eurocents these days, it makes me wonder.
In fact I might even be better off building a cold stored once-a-week backup server instead?
I'm just looking to prevent my NAS from sucking back too many energy bill euros,
and 'sleeping' some drives, to me, seems the most obvious option.

Any thoughts/advice?

Ironically enough, Allan Jude fielded a question similar to this on the BSD Now podcast recently. I don't have it at my fingertips, but a couple of other things he mentioned are

• Each hard drive has a fixed number of startups on the motor, as was mentioned in this thread, so spinning them up and down actually shortens the lifespan of the drives, as compared to just letting them run. Whether the data is important enough for you to run the risk is obviously up to you.
• Making sure that you are not powering down the drives in mid-scrub, though newer versions of OpenZFS has a feature flag that will allow a scrub to continue when the system is powered back on. However, if your scrubs take six months to complete, then your data is not as well protected as you think it is.
• And related, regular scrubs are part of that maintenance that you need for data health...So not doing them at all is a Bad Thing as well.