When upgrading your Ubuntu 20.04 installation, you may see a message like this:

Setting up grub-efi-amd64-signed (1.142.6+2.04-1ubuntu26.4) ...
Unknown device "/dev/disk/by-id/*": No such file or 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
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)

This error occurs because our VPS do not use EFI.  To correct this fault run the following commands:

apt-get install -y grub-pc 'grub-efi*-' && grub-install /dev/vda
sed -Ei 's/^(GRUB_CMDLINE_LINUX_DEFAULT=)"[^"]*"/\1"quiet nosplash net.ifnames=0 vga=770"/' \
    /etc/default/grub && update-grub