Something has been happening here occasionally, ZFS Metadata corruption. The tl;dr is that ZFS Metadata corruption should not be occurring unless the user has a non-redundant pool AND has changed the default of redundant_metadata=all. Or has bad hardware. Certainly not at the rate we seem to be see…

[image] etorix: And how can ZFS fail to update labels on some drives in a pool for hours, if not for days? :scream: Purely from hardware failure? Without the pool being faulted? Hmm, I wonder if the Linux storage driver is holding back writes of certain data because it sees that it is constan…

I’ve had weird issues crop up due to a bad PSU. I have no doubt a bad UPS could make the PSU fail also. For example, years ago one of my PSUs was fried due to incessant power interruptions. A bad UPS might manage that also. A lot of factors go into component longevity and I was really surprised wh…

Just some general thoughts/personal opinons. [image] Arwen: Again UPSes are not required for ZFS on-disk consistency; I’m not a UPS evangelist, but this isn’t quite the whole story. One point I will say in this regard. From a hardware perspective, regardless of software safety belts, weird …

[image] Constantin: PSU started failing and creating all sorts of weird errors even as the maximum system load was 120W I wonder what kind of errors there were and how you found out that it was the PSU.

I’ll have to look for that in the old forum. Hang on a sec. Your wish is my command . There is a follow on titled descent into unhappiness as electrical gremlins made ZFS declare my pool dead. So fun.

[image] swc-phil: I wonder what kind of errors there were and how you found out that it was the PSU. Failing PSUs can cause issues regardless of the power draw. All the sorts of internal compensation circuits and capacitors and stuff would all be sized relative to the maximum draw of the powe…

There is a PSU tier list , btw. Can’t say anything about its reliability…

Yes, there are plenty of these that exist out there still. LTT has one thats pretty actively maintained, as another example. https://www.lttlabs.com/categories/power-supplies But the moral of the story is, if you are delivering unstable voltage to a drive (regardless of solid state vs mechanical),…

@Arwen thanks for the posting. Metadata corruption of course has been on my mind as of late due to the uptick in postings about metadata corruption. I suspect most of the metadata problems are due to not using good hardware, most specifically not using ECC RAM, but we know there has been an ECC ca…

[image] NickF1227: [image] Arwen: Again UPSes are not required for ZFS on-disk consistency; I’m not a UPS evangelist, but this isn’t quite the whole story. My original point stands. However, having personally experienced a brownout lasting minutes, (which happened to me just a few wee…

ZFS Metadata - How it works, plus discussion on corruption

TrueNAS General

Constantin August 3, 2025, 5:18pm 21

I put in a feature request along the same lines a while ago and it was not taken up. I concur that better your-pool-couldn’t-be-imported-advice than “your pool is dead, rebuild from backup” would be great.

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ZFS Metadata - How it works, plus discussion on corruption

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