Where it explains the "special_small_blocks=size" property, zfsprops(8) says: "See zpool(8) for more details on the special allocation class."
However, the relevant explanation is not found in zpool(8), but rather in zpoolconcepts(8).
As this manual page is actually from the OpenZFS project, I've opened a pull request about it upstream.
I hope I did the right thing.
It's definitely right to inform upstream, thanks for that! :)
I don't know how quickly such upstream changes land in FreeBSD, though, so it might still be worth patching on our side independently.
Created attachment 224300 [details]
Patch to fix incorrect reference to zpool(8) in zfsprops(8)
Actually, since it is merged upstream, I believe we should wait for it to be imported back.
+ CC mm@