Debian VM Installation on FreeBSD

I wanted to create a base Debian VM that I can clone and use for the rest of my home lab. The following are some technical notes for how to do that.

Create the VM with BHyve

Add the ISO to BHyve:

vm iso https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-12.11.0-amd64-netinst.iso 

You will need to create the VM before picking installation media. Here are the settings I use the following, based on the defaults with some tweaks for CPU/Memory:

/mnt/vm/.templates # cat debian.conf 
loader="grub"
cpu=4
memory=4096M
network0_type="virtio-net"
network0_switch="public"
disk0_type="ahci-hd"
disk0_name="disk0.img"
grub_run_partition="1"
grub_run_dir="/boot/grub"

The defaults are located at /usr/local/share/examples/vm-bhyve, and need to be copied into your local config area. My configuration has the templates at /mnt/vm/.templates, for instance.

Once you’ve copied the configuration into place, create the VM. Here I request 100GB of disk when creating this VM:

vm create -s 100G -t debian deb-base

Start the installation, and attach to the console:

vm install deb-base debian-12.11.0-amd64-netinst.iso

At this point, the VM should be running with the installer going.

Attaching to the console:

vm console deb-base

To exit the console, use ~^D (tilde, plus CTRL-D).

Post-install Configuration

I run an update after initial installation, and immediately configure my user to use sudo.

apt update
apt upgrade
apt install sudo
echo "lincoln ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers

Finally, I copy the key into place from my host machine:

ssh lincoln@<VM IP> mkdir .ssh
scp ~/.ssh/id_ecdsa.pub lincoln@<VM IP>:~/.ssh/authorized_keys

Now all cloned VMs will have my key on them and sudo prepared.

Cloning a VM

To create a new VM from the base VM, simply use the clone subcommand. For instance, to create a new Debian VM called deb01:

vm clone deb-base deb01

The clone should immediately boot. Once it’s running, you will need to complete a few more preparation steps before it’s usable. It’s a good practice to generate the SSH keys and the machine ID, so as not to collide with the template VM. Run the following as root:

# Regenerate SSH keys
rm -f /etc/ssh/ssh_host_*
dpkg-reconfigure openssh-server
# Regenerate Machine ID
rm -f /etc/machine-id
dbus-uuidgen --ensure=/etc/machine-id

Next steps

At this point, I configure my network with a DHCP reservation for the VM and further customize the VM with Ansible.

I also set the VM to autostart on boot, if desired, by editing /etc/rc.conf:

vm_list="deb01 deb02 deb03"