Re: sysctl: unknown oid 'vfs.zfs.min_auto_ashift'

From: Yasuhiro Kimura <yasu@FreeBSD.org>
Subject: sysctl: unknown oid 'vfs.zfs.min_auto_ashift'
Date: Mon, 15 Sep 2025 07:18:15 +0900 (JST)

> 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?

I found following commit log.

commit 70999532eea5
Merge: 5f9a05e57405 7939bad5e792
Author:     Martin Matuska <mm@FreeBSD.org>
AuthorDate: Wed Sep 10 17:28:34 2025 +0200
Commit:     Martin Matuska <mm@FreeBSD.org>
CommitDate: Wed Sep 10 17:28:34 2025 +0200

    zfs: merge openzfs/zfs@7939bad5e
    
    Notable upstream pull request merges:
     #15869 ee7c36264 Add description of default sorting behavior to zfs_list.8
     #17375 ced72fdd6 tunables: remove legacy FreeBSD aliases
     #17600 1da2c30be Update pam_zfs_key.c default path for FreeBSD
     #17632 b6bd3228b Synchronize the update of feature refcount
     #17645 59f8f5dfe zfs_vnops_os.c: Add support for the _PC_CLONE_BLKSIZE name
     #17665 0d54ae288 zdb: Fix format strings on 32-bit systems
     #17673 976f76534 Update compatibility.d files
     #17699 e3c3e86c0 Fix wrong dedup_table_size for legacy dedup
     #17704 e29bfa5bd Fix warnings about sha2_is_supported on FreeBSD/i386
     #17706 a2424312c Fix the build on 32-bit FreeBSD with GCC
    
    Obtained from:  OpenZFS
    OpenZFS commit: 7939bad5e79225288a2580e8ea217f5c6f616db2

And commit ced72fdd6 actually removes vfs.zfs.min_auto_ashift.

From: Mark Millard <marklmi@yahoo.com>
Subject: sysctl: unknown oid 'vfs.zfs.min_auto_ashift' [legacy dropped; only vfs.zfs.vdev.min_auto_ashift now]
Date: Sun, 14 Sep 2025 16:49:16 -0700

> # 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

Thanks. I changed original line to 'vfs.zfs.vdev.min_auto_ashift=12',
rebooted system and now error message isn't displayed.

---
Yasuhiro Kimura