RAIDZ2 Expansion: Unexplained 10TB Space Loss & 2x Overhead

[LarsR]

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24.10 RC2 Raidz expansion caused miscalculated available storage

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 expansion, and I had a need to reboot). After all expansion was completed, it seems like the usable capacity value wasn’t updated to properly reflect the new capacity. [image] I did try the zfs rebal…

TLDR:
There’s a bug with space reporting