[PVE-User] ZFS Upgrade...

[Alwin Antreich]

Hi Marco,  
  

September 30, 2025 at 6:37 PM, "Marco Gaiarin" <[gaio at lilliput.linux.it](mailto:gaio at lilliput.linux.it?to=%22Marco%20Gaiarin%22%20%3Cgaio%40lilliput.linux.it%3E)\> wrote:

> Mandi! Alwin Antreich via pve-user  
> In chel di\` si favelave...  
>   
> 
> > > So, implicitly you confirm that it is GRUB that have some incompatibilities,  
> > > not GRUB in legacy mode... I've understood well?
> > 
> >   
> > To my understanding, yes. Historically grub didn't (or still doesn't) support all features of a zfs pool on root. That's why the installer selects grub or systemd-boot \[0\] depending on system.
> 
>   
> So, practically:  
>   
> 1) if i use systemd-boot i'm safe and i can safely upgrade boot zpool  
>   
> 2) if i use GRUB, both in:  
> 2a) legacy  
> or  
> 2b) UEFI  
> mode, i'm in danger and if i upgrade boot pool, system get unbootable.  
>   
>   
> Clearly, if i have a system taht boot in UEFI GRUB, i can upgrade bootloader  
> to systemd-boot (How?).  
See here. https://pve.proxmox.com/wiki/ZFS:_Switch_Legacy-Boot_to_Proxmox_Boot_Tool

Cheers,
Alwin