Grub crashes on Apt upgrade (grub-install: error: cannot find EFI directory)

I have multiple servers with Ubuntu 18.04.5 LTS. After running apt-get upgrade I received this error on each of my servers.

Setting up grub-efi-amd64 (2.04-1ubuntu44) ...
Creating config file /etc/default/grub with new version
Installing for x86_64-efi platform.
grub-install: error: cannot find EFI directory.
Failed: grub-install --target=x86_64-efi
WARNING: Bootloader is not properly installed, system may not be bootable
Setting up grub-efi-amd64-signed (1.167~18.04.1+2.04-1ubuntu44) ...
Installing for x86_64-efi platform.
grub-install: error: cannot find EFI directory.
dpkg: error processing package grub-efi-amd64-signed (--configure): installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
Setting up grub-efi (2.02-2ubuntu8.23) ...
Processing triggers for install-info (6.5.0.dfsg.1-2) ...
Processing triggers for systemd (237-3ubuntu10.47) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
Processing triggers for ureadahead (0.100.0-21) ...
Errors were encountered while processing: grub-efi-amd64-signed
E: Sub-process /usr/bin/dpkg returned an error code (1)

I tried

apt-get remove --purge grub*
apt-get install grub-efi

I received the same error.

parted -l

Model: ATA INTEL SSDSC2BB48 (scsi)
Disk /dev/sda: 480GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags 1 2097kB 538MB 536MB primary ext4 boot, raid 2 538MB 480GB 479GB primary ext4 raid 3 480GB 480GB 536MB primary linux-swap(v1)
Model: ATA INTEL SSDSC2BB48 (scsi)
Disk /dev/sdb: 480GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags 1 2097kB 538MB 536MB primary ext4 boot, raid 2 538MB 480GB 479GB primary ext4 raid 3 480GB 480GB 536MB primary linux-swap(v1)
Model: Linux Software RAID Array (md)
Disk /dev/md2: 479GB
Sector size (logical/physical): 512B/4096B
Partition Table: loop
Disk Flags:
Number Start End Size File system Flags 1 0.00B 479GB 479GB ext4
Model: Linux Software RAID Array (md)
Disk /dev/md1: 536MB
Sector size (logical/physical): 512B/4096B
Partition Table: loop
Disk Flags:
Number Start End Size File system Flags 1 0.00B 536MB 536MB ext4

lsblk -o name,mountpoint,label,size,fstype,uuid,partuuid | egrep -v "^loop"

NAME MOUNTPOINT LABEL SIZE FSTYPE UUID PARTUUID
sda 447.1G
├─sda1 511M linux_raid_member c364765a-3520-35be-a4d2-adc226fd5302 b6b3ff9d-01
│ └─md1 /boot /boot 511M ext4 97d71870-bf9f-417c-b574-a2029e1d3957
├─sda2 446.1G linux_raid_member 7dd31816-8619-f750-a4d2-adc226fd5302 b6b3ff9d-02
│ └─md2 / / 446.1G ext4 ff05852d-7f0f-4f80-ab89-cfe3397b6411
└─sda3 [SWAP] swap-sda3 511M swap 86e64442-6f61-4606-9e87-18af89b5feab b6b3ff9d-03
sdb 447.1G
├─sdb1 511M linux_raid_member c364765a-3520-35be-a4d2-adc226fd5302 5c50a432-01
│ └─md1 /boot /boot 511M ext4 97d71870-bf9f-417c-b574-a2029e1d3957
├─sdb2 446.1G linux_raid_member 7dd31816-8619-f750-a4d2-adc226fd5302 5c50a432-02
│ └─md2 / / 446.1G ext4 ff05852d-7f0f-4f80-ab89-cfe3397b6411
└─sdb3 [SWAP] swap-sdb3 511M swap 9f3d62fc-3c8c-474c-b844-fe7e325d19a2 5c50a432-03

cat /etc/fstab

# <file system> <mount point> <type> <options> <dump> <pass>
/dev/md2 / ext4 errors=remount-ro,discard 0 1
/dev/md1 /boot ext4 errors=remount-ro,discard 0 1
/dev/sda3 swap swap defaults 0 0
/dev/sdb3 swap swap defaults 0 0
proc /proc proc defaults 0 0
sysfs /sys sysfs defaults 0 0

1 Answer

The solution for me was :

sudo apt remove grub-efi-amd64-signed
sudo apt install grub-pc

On a OVH server (kimsufi)