vagrant box debian/bullseye64: different FS and grub-pc non-interactive configuration

[Bernd Schatz <bernd.schatz@gmx.net>]

Hi,

I create vagrant-boxes (libvirt and virtualbox) from debian/testing64

For avoiding the interactive menu in the case of a grub-pc update,
i added this line to my provisioning-shell script:


sudo debconf-communicate  <<< "set grub-pc/install_devices /dev/sda"


Now i switched to the new debian/bullseye64 box,
and there it fails for libvirt.
The reason is that the libvirt-box uses another filesystem:


$ vagrant box list | grep bullseye
debian/bullseye64 (libvirt, 11.20210228.1)
$ vagrant ssh
vagrant@bullseye:~$ df -kh /
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        20G  4.1G   15G  22% /



on virtualbox:

$ vagrant box list | grep bullseye
debian/bullseye64 (virtualbox, 11.20210228.1)
$ vagrant ssh
vagrant@bullseye:~$ df -khT /
Filesystem     Type  Size  Used Avail Use% Mounted on
/dev/sda1      ext4   20G  4.4G   15G  24% /


is it possible to

1) use the same filesystem

and/or

2) add this line to the basebox:
sudo debconf-communicate  <<< "set grub-pc/install_devices /dev/sda"



--
Bernd