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My 71 TiB ZFS NAS After 10 Years and Zero Drive Failures

louwrentius.com

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Re: My 71 TiB ZFS NAS After 10 Years and Zero Drive Failures

#31

Post by monocasa »

mvanbaak wrote: post #9

the 'secret' is not that you turn them off. it's simply luck. I have 4TB HGST drives running 24/7 for over a decade. ok, not 24 but 8, and also 0 failures. But I'm also lucky, like you. Some of the people I know have several RMAs with the same drives so there's that. My main question is: What is it that takes 71TB but can be turned off most of the time? Is this the server you store backups?

In fact, the conventional wisdom for a long time was to not turn them off if you want longevity. Bearings seize when cold for instance.

Re: My 71 TiB ZFS NAS After 10 Years and Zero Drive Failures

#32

Post by louwrentius »

rkagerer wrote: post #22

I have a similar-sized array which I also only power on nightly to receive backups, or occasionally when I need access to it for a week or two at a time. It's a whitebox RAID6 running NTFS (tried ReFS, didn't like it), and has been around for 12+ years, although I've upgraded the drives a couple times (2TB --> 4TB --> 16TB) - the older Areca RAID controllers make it super simple to do this. Tools like Hard Disk Senti…

I bought the HGSTs specifically because they showed good stats in those Backblaze drive stats that they just started to publish back then.

Re: My 71 TiB ZFS NAS After 10 Years and Zero Drive Failures

#35

Post by louwrentius »

renewiltord wrote: post #30
louwrentius wrote: post #26

Earlier quoted context omitted.

5 drives failed in Q1 2024. 8 died in Q2. That is still a very low failure rate.

Drives have a bathtub curve, but if you want you can be conservative and estimate first year failure rates throughout. So that's p=5/10000 for drive failure. So chance of no-failure per year (because of our assumption) is 1-p. So, chance of no-failure per ten year is (1-p)^10 or about 99.5%

Is that for one drive, or for all 24 drives to survive 10 years?

Re: My 71 TiB ZFS NAS After 10 Years and Zero Drive Failures

#36

Post by dastbe »

louwrentius wrote: post #16
mvanbaak wrote: post #9

the 'secret' is not that you turn them off. it's simply luck. I have 4TB HGST drives running 24/7 for over a decade. ok, not 24 but 8, and also 0 failures. But I'm also lucky, like you. Some of the people I know have several RMAs with the same drives so there's that. My main question is: What is it that takes 71TB but can be turned off most of the time? Is this the server you store backups?

It can be luck, but with 24 drives, it feels very lucky. Somebody with proper statistics knowledge can probably calculate the risk with a guestimated 1% yearly failure rate how likely it would be to have all 24 drives remaining. And remember, my previous NAS with 20 drives also didn't have any failures. So N=44, how lucky must I be? It's for residential usage, and if I need some data, I often just copy it over 10Gbit…

it's (1-p)^24^10, where p is drive failure rate per year (assuming it doesn't go up over time). so at 1% that's about 9% or a 1/10 chance of this result. Not exactly great, but not impossible.

the backblaze rates are all over the place, but it does appear they have drives that this rate or lower: https://www.backblaze.com/blog/backblaze-drive-stats-for-q2-...

Re: My 71 TiB ZFS NAS After 10 Years and Zero Drive Failures

#37

Post by louwrentius »

ggm wrote: post #25
louwrentius wrote: post #3

Earlier quoted context omitted.

> There have been drives where power cycling was hazardous. I know about this story from 30+ years ago. It may have been true then. It may be even true now. Yet, in my case, I don't power cycle these drives often. At most a few times a month. I can't say or prove it's a huge risk. I only believe it's not. I have accepted this risk for over 15+ years. Update: remember that hard drives have an option to spin down when…

I debated posting because it felt like shitstirring. I think overwhelmingly what you're doing is right. And if a remote power on eg WOL works on the device, so much the better. If I could wish for one thing, it's mods to code or documentation of how to handle drive power down on zfs. The rumour mill is zfs doesn't like spindown.

I did try using HDD spindown on ZFS but I remember (It's a long time ago) that I encountered too many vague errors that scared me and I just disabled spindown all together.

Re: My 71 TiB ZFS NAS After 10 Years and Zero Drive Failures

#40

Post by louwrentius »

anjel wrote: post #34

Ca't help but wonder how much electricity would have been consumed if you had left it on 24/7 for ten years...

On the original blog it states that the machine used 200W idle. Thats 4,8 KWh a day. 17520 KWh over 10 years? At around 0.30 euro per KWh that's 5K+ if I'm not mistaken.
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