[Solved] proxmox-boot-tool: "System currently booted with legacy bios" - Am I safe to reboot?

[Helmut101]

I hit the issue where `grub-probe` complains with "error: compression algorithm inherit not supported", likely because sanoid did a snapshot of my ZFS root/boot partition, as described here: https://github.com/openzfs/zfs/issues/15261

I followed https://pve.proxmox.com/wiki/ZFS:_Switch_Legacy-Boot_to_Proxmox_Boot_Tool and used the two available 512 VFAT partitions to init them with proxmox-boot-tool:

```
proxmox-boot-tool init /dev/sdk2
proxmox-boot-tool init /dev/sdl2
```

This worked, but now I am seeing the following:
```
~# proxmox-boot-tool status
Re-executing '/usr/sbin/proxmox-boot-tool' in new private mount namespace..
System currently booted with legacy bios
985C-E0C5 is configured with: grub (versions: 6.5.13-6-pve, 6.8.12-2-pve, 6.8.8-4-pve)
985D-4690 is configured with: grub (versions: 6.5.13-6-pve, 6.8.12-2-pve, 6.8.8-4-pve)
```

Is it safe for me to reboot, even though I am seeing `System currently booted with legacy bios`? How can I know whether my system will be able to boot, before rebooting?

Running:
```
grub-probe /rpool/ROOT
```

.. still gives me:
> grub-probe: error: compression algorithm inherit not supported

I disabled compression on the boot pool, but this has no effect:
```
zfs set compression=off rpool
```

I did a `proxmox-boot-tool refresh`, but I still get the "System currently booted with legacy bios":
```
~# proxmox-boot-tool refresh
Running hook script 'proxmox-auto-removal'..
Running hook script 'zz-proxmox-boot'..
Re-executing '/etc/kernel/postinst.d/zz-proxmox-boot' in new private mount namespace..
Copying and configuring kernels on /dev/disk/by-uuid/985C-E0C5
Copying kernel 6.5.13-6-pve
Copying kernel 6.8.12-2-pve
Copying kernel 6.8.8-4-pve
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-6.8.12-2-pve
Found initrd image: /boot/initrd.img-6.8.12-2-pve
Found linux image: /boot/vmlinuz-6.8.8-4-pve
Found initrd image: /boot/initrd.img-6.8.8-4-pve
Found linux image: /boot/vmlinuz-6.5.13-6-pve
Found initrd image: /boot/initrd.img-6.5.13-6-pve
done
Copying and configuring kernels on /dev/disk/by-uuid/985D-4690
Copying kernel 6.5.13-6-pve
Copying kernel 6.8.12-2-pve
Copying kernel 6.8.8-4-pve
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-6.8.12-2-pve
Found initrd image: /boot/initrd.img-6.8.12-2-pve
Found linux image: /boot/vmlinuz-6.8.8-4-pve
Found initrd image: /boot/initrd.img-6.8.8-4-pve
Found linux image: /boot/vmlinuz-6.5.13-6-pve
Found initrd image: /boot/initrd.img-6.5.13-6-pve
done

```

 

[Helmut101]

Coming back here to confirm reboot worked :thumbsup:

I think this line in the documentation indicates that "System currently booted with legacy bios" is Ok:

> In the end, both legacy BIOS or UEFI can use this setup for booting.