I have Proxmox 8 installed on my Mac Pro 2008 which I’ve run for a few years. Noticing that there was recently an update to 9, I followed the inplace upgrade instructions here, followed all the prompts during install as per the guide and everything went well.
Before:
After upgrade and reboot:
The only question I ran into was this prompt about updating an UEFI boot loader:
Removable bootloader found at '/boot/efi/EFI/BOOT/BOOTX64.efi', but GRUB packages not set up to update it!
Run the following command:
echo 'grub-efi-amd64 grub2/force_efi_extra_removable boolean true' | debconf-set-selections -v -u
Since I’ve tried installing OCLP on this Mac Pro before, I assumed this was something to do with that … so ignored it, rebooted…. and everything was ok …