I have a server with 6x18tb (16.37TiB) drives in RAIDz2, and due to hardware limitations, needed to start with 4 drives and expand later. Using 24.10 RC2, I extended my vdev twice, and during the second vdev expansion, I rebooted the system (as zfs documentation said it was safe to reboot during ex…

[image] yorick: Another 3 years? :sweat_smile: That’s the equivalent of one week in “GIMP 3 development time”. What’s going to arrive first? The “Year of the Linux Desktop” or the “Year of GIMP 3’s Release”?

If there was data loss with basic usage of the system at this point in the development I would be very concerned. For me it’s more of an annoyance that the storage usage and availability isn’t reporting correctly. As long as 24.10.0 or 1-2 iterations later fixes the issue for me the tradeoff is wort…

If I had the drive space to do this with ~15TB I would have done it this way. That being said I’m not buying extra drives just to temporarily copy a bunch of data to them before recreating the new pool. This becomes even tougher as data usage increases. Also, please be MUCH less than 3 years😅

I don’t work in tech, but if I reported that something using X amount of something but I knew it was actually using Y amount and it caused a negative outcome I’d expect to get fired. OTOH, the reality is that no boss of mine would ever figure what had gone wrong so :person_shrugging:

[image] winnielinnie: Don’t ask how! Something to do with parity, calculations, block-striping, vdev width, new vs old math, “compression” (for a video file, of all things), and… good ol’ ZFS magic! So… what ya do, is you work out how many raidz stripes are filled… then you multiply that by t…

[image] winnielinnie: A 30% discrepancy is not acceptable. Try a 2wZ1 to 10wZ1 expansion…

The correct implementation in Truenas should have been to expand the vdev, run the scrub, and then immediately run the rebalance script, not as a random user, but as part of the expansion process and then force the recalculation of pool size. Now someone will come along as say “but we couldn’t do t…

truenas/zfs/blob/3b78e86ec9b76c7df855991982fae64b9cda7266/module/zfs/dmu.c#L2790 DB_DNODE_ENTER(db); dmu_object_info_from_dnode(DB_DNODE(db), doi); DB_DNODE_EXIT(db); } /* * Faster still when…

[image] awalkerix: ZFS space accounting is complicated. Understatement of the century.

24.10 RC2 Raidz expansion caused miscalculated available storage

TrueNAS General

winnielinnie October 17, 2024, 9:51pm 73

It’s actually not that complicated. There’s a quick formula you can use to demystify how much total capacity you actually have and how much space is available.

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24.10 RC2 Raidz expansion caused miscalculated available storage

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