Re: gptzfsboot cannot boot from ZFS (mirror) with "can't read MOS of pool znewroot" (FreeBSD 13.5-STABLE)
Date: Thu, 03 Apr 2025 16:53:54 UTC
April 3, 2025 at 6:35 PM, "Miroslav Lachman" <000.fbsd@quip.cz mailto:000.fbsd@quip.cz?to=%22Miroslav%20Lachman%22%20%3C000.fbsd%40quip.cz%3E > wrote: > > > > ZFS: i/o error - all block copies unavailable > > ZFS: can't read MOS of pool znewroot > > As a hack I'm using `gtpboot` & small `freebsd-ufs` partiton with only `/boot` directory. > > But I hate this hack, as system update becomes cumbersome, and I cannot convert this system to UEFI boot (because `loader.efi` "Failed to find bootable partition"). > > What is wrong with my ZFS pool and how could I fix it? > > > Is it possible that you have disk drives larger than 2TB and the boot data is written somewhere after that 2TB barrier? It is exactly 2T disks: Model Family: HGST Ultrastar 7K6000 Device Model: HGST HUS726020ALE610 Serial Number: K5HPZZLD LU WWN Device Id: 5 000cca 25ed8179e Firmware Version: APGNTD05 User Capacity: 2,000,398,934,016 bytes [2.00 TB] Model Family: Toshiba MG04ACA... Enterprise HDD Device Model: TOSHIBA MG04ACA200EY Serial Number: X71EK0F4F7QB LU WWN Device Id: 5 000039 81bd80140 Firmware Version: FQ1B User Capacity: 2,000,398,934,016 bytes [2.00 TB] > I solved it by creating small partitions on the beginning of the drives - about 20GB to contain boot and all the FreeBSD system data. I've created freebsd-ufs partitons, cutting space from swap, when it stops work after one disk trplacement, as it is remote server, it is hard to do complex things, and I needed solution ASAP :) -- // Lev Serebryakov