Re: Set ZFS pool ashift=14 for FreeBSD root pools?

On Tue, 12 May 2026 at 17:36, Alan Somers <[email protected]> wrote:
>
> On Tue, May 12, 2026 at 8:46 AM Lionel Cons <[email protected]> wrote:
> >
> > On Tue, 12 May 2026 at 12:51, vermaden <[email protected]> wrote:
> > >
> > > > How can I set the ZFS pool ashift for root pools
> > > > to a value like 14 (for FreeBSD inside a VM)?
> > > >
> > > > Lionel
> > >
> > >
> > >
> > > This has to be done before ZFS pool creation and it can be set like that:
> > >
> > > # sysctl vfs.zfs.min_auto_ashift=14
> >
> > How can I do this at install time for all root pools?
> >
> > Lionel
>
> I don't know how to do it if you use the vanilla install CD.  Maybe
> you could boot the install CD, exit to a shell, set the sysctl, and
> reenter the TUI.
>
> But if you have lots of machines to install, you might consider
> spinning a custom CD, and if you do that then you can easily set the
> sysctl or set "-o ashift=14" in ZFSBOOT_BOOT_POOL_CREATE_OPTIONS.  See
> the SCRIPTING section of bsdinstall(8) for details.

Plain ISO image.

During install I get the question for ZFS options, with noatime being
in the default string (which we remove, because noatime breaks
software...) ... can I put the option in there?

Lionel