Repair proxmox7 grub after apt upgrade

[teriblus]

I'm using the proxmox7 template on my dedicated server.
The first thing I did after install is apt update && apt upgrade, this resulted in an error with grub-pc unable to write on /dev/md

The support directed me to this guide, and it was helpful, but not quite enough. What worked for me was :

--- boot en mode rescue64-pro ----

root@rescue:~# mount /dev/md126 /mnt
root@rescue:~# mount /dev/md125 /mnt/boot
root@rescue:~# mount -o bind /proc /mnt/proc
root@rescue:~# mount -o bind /sys /mnt/sys
root@rescue:~# mount -o bind /dev /mnt/dev
root@rescue:~# chroot /mnt /bin/bash
root@rescue:/# mount /dev/sda1 /boot/efi
root@rescue:/# grub-install --efi-directory=/boot/efi/
root@rescue:/# umount /boot/efi     
root@rescue:/# mount /dev/sdb1 /boot/efi
root@rescue:/# grub-install --efi-directory=/boot/efi/
root@rescue:/# reboot

---- boot sur hd -----