hi
workaround on fresh install proxmox 5.2
install proxmox
reboot
boot from usb proxmox stick on "rescue boot"
im my case with mirror between 2 disk
mkfs.vfat /dev/sdX1
mkfs.vfat /dev/sdY1
for checking if everything is ok
mount /dev/sdX1 /boot/efi
grub-install /dev/sdX1
grub-install /dev/sdY1
reboot
remove usb stick
ok
regards
workaround on fresh install proxmox 5.2
install proxmox
reboot
boot from usb proxmox stick on "rescue boot"
im my case with mirror between 2 disk
mkfs.vfat /dev/sdX1
mkfs.vfat /dev/sdY1
for checking if everything is ok
mount /dev/sdX1 /boot/efi
grub-install /dev/sdX1
grub-install /dev/sdY1
reboot
remove usb stick
ok
regards