sysctl: unknown oid 'vfs.zfs.min_auto_ashift' [legacy dropped; only vfs.zfs.vdev.min_auto_ashift now]

Yasuhiro Kimura <yasu_at_FreeBSD.org> wrote on
Date: Sun, 14 Sep 2025 22:18:15 UTC :

> 16.0-CURRENT main-n280279-b0e7b55a0e90 amd64.
> 
> There is following line in /etc/sysctl.conf (IIUC bsdinstall adds it
> at install time if system is zfs-root).
> 
> vfs.zfs.min_auto_ashift=12
> 
> Today I noticed following error message is displayed when system is
> booted.
> 
> sysctl: unknown oid 'vfs.zfs.min_auto_ashift' at line 9
> 
> And I get same error if I execute `sysctl vfs.zfs.min_auto_ashift`
> from command line.
> 
> Does this mean vfs.zfs.min_auto_ashift is removed? If so, is it just
> unnecessary any more or any alternative provided?


# uname -apKU
FreeBSD 7950X3D-ZFS 16.0-CURRENT FreeBSD 16.0-CURRENT main-n280292-3c60ea77649d GENERIC-NODEBUG amd64 amd64 1600000 1600000

It is a boot-from-ZFS-based-root context as well.

# sysctl -a | grep _ashift
vfs.zfs.vdev.max_auto_ashift: 14
vfs.zfs.vdev.min_auto_ashift: 12
vfs.zfs.vdev.file.physical_ashift: 9
vfs.zfs.vdev.file.logical_ashift: 9


So now there is just: vfs.zfs.vdev.min_auto_ashift


===
Mark Millard
marklmi at yahoo.com