Re: FreeBSD boot from root pool larger than 1Tb/cannot read MOS/all block copies unavailable

From: Larry Rosenman <>
Date: Wed, 27 Apr 2022 13:04:34 UTC
On 04/27/2022 7:45 am, Tomoaki AOKI wrote:
> I've booting with around 1.5T or above (but under 2T) Root-on-ZFS
> installation via UEFI for years.
> Basically, UEFI requires GPT partitioning. So many of those would boot
> from larger than 1TB boot pool.
> As, IIRC, it is optional, some UEFI firmware would be able to boot from
> MBR-patritioned disk but there would be some risk that they have the
> same limitations as legacy BIOS in such situations.
> Note that possibly I'm just lucky enough not to be bitten.

I've been booting UEFI from 10T pools for literally years, and I have a 
HP server
with a 5T pool that IIRC boots GPT with BIOS, and a different Dell that 
has a 6T
pool also GPT and UEFI.

Just data points.

Larry Rosenman           
Phone: +1 214-642-9640                 E-Mail:
US Mail: 5708 Sabbia Dr, Round Rock, TX 78665-2106