Learn FreeBSD - bhyve & Virtualization

#Introduction

In the previous episode 15, you ran jails for containerization. Now we move up to full virtualization with bhyve — FreeBSD's built-in type-2 hypervisor that runs other operating systems completely: Linux, FreeBSD, even Windows. This episode guides you from the basics of bhyve and bhyvectl, through the more convenient vm-bhyve frontend, to the practice of installing VMs with UEFI, virtio storage, and tap/bridge networking.

#The bhyve Concept

#FreeBSD's Built-in Hypervisor

bhyve is a hypervisor integrated with the FreeBSD kernel. It leverages hardware virtualization (VT-x/AMD-V) and offers lightweight, high-performance virtualization.

The main difference from jails: bhyve VMs don't share the host kernel — each VM runs its own kernel in full isolation. This means more overhead, but far more isolation and flexibility.

Info

Jails and bhyve complement each other: use jails for lightweight services that can share the kernel, and bhyve for full operating system needs, custom kernels, or strict isolation. Many production setups use both at once.

#Checking Support

Make sure the hardware and module are ready:

Memeriksa dukungan bhyve

sysctl kern.vm_guest
kldstat | grep vmm
kldload vmm

vmm is the bhyve kernel module. If it isn't loaded yet, kldload vmm will load it.

#Using bhyve and bhyvectl

#Running a VM Manually

bhyve can be run directly with a long command-line argument list. A basic FreeBSD VM example:

Menjalankan VM dengan bhyve

bhyve -c 2 -m 2G \
  -s 0:0,hostbridge \
  -s 1:0,lpc \
  -s 2:0,ahci-hd,/vm/freebsd.img \
  -s 3:0,virtio-net,tap0 \
  -l com1,stdio \
  -H -P freebsd01

The -c argument sets the CPU, -m the memory, -s defines virtual devices, and -H allows hypervisor exits. The final name (freebsd01) is the VM's identity.

#Stopping a VM

bhyvectl manages a VM's lifecycle:

Menghentikan VM

bhyvectl --destroy --vm=freebsd01

#The Modern Frontend: vm-bhyve

vm-bhyve simplifies everything — VM management like a modern tool with lists, templates, and file-based configuration.

#Installation and Configuration

Menginstal vm-bhyve

pkg install vm-bhyve
sysrc vm_enable="YES"
sysrc vm_dir="zfs:tank/vm"

Set the VM data directory — here using the ZFS dataset tank/vm, mounted at /vm. Create a default network:

Membuat jaringan vm-bhyve

vm switch create public
vm switch add public em0

#Creating and Installing a VM

Put the ISO image in the iso directory, then create the VM:

Membuat VM FreeBSD

vm create -t freebsd-ufs freebsd01
vm install freebsd01 /vm/iso/FreeBSD-15.1-RELEASE-amd64-disc1.iso
vm console freebsd01

vm install attaches the ISO and boots into the installer; vm console opens a serial console for interaction.

Success

vm-bhyve hides the complexity of raw bhyve arguments behind templates and concise commands. For both production and homelab, it's the most convenient way to run VMs on FreeBSD.

#Managing VMs

The daily commands you'll use often:

Mengelola VM

vm list
vm start freebsd01
vm stop freebsd01
vm console freebsd01
vm info freebsd01

#Virtualization Practice

#UEFI Boot

bhyve supports both UEFI (CSM) and UEFI-native firmware. vm-bhyve provides UEFI templates for modern systems:

Mengatur firmware UEFI

vm configure freebsd01
vm set freebsd01 bootrom=bhyve_efi.fd

#Virtio Storage

Virtio is a paravirtualization driver that gives the best I/O performance. Use virtio-blk disks and virtio-net NICs for VMs:

Menggunakan perangkat virtio

vm set freebsd01 disk0_type=virtio
vm set freebsd01 nic0_type=virtio

#Tap and Bridge Networking

VM networking uses tap and bridge pairs: tap is the virtual interface at the VM end, and the bridge connects it to the host network:

Memeriksa tap dan bridge

ifconfig tap0
ifconfig bridge0

#VM Snapshots

With ZFS as storage, VM snapshots are done at the dataset level:

Membuat snapshot VM

zfs snapshot tank/vm/freebsd01@sebelum-update
zfs list -t snapshot | grep freebsd01

Warning

For a consistent snapshot, shut down or pause the VM first, or use guest-aware snapshot features where available. A filesystem snapshot without application synchronization can produce inconsistent data.

#Running Linux on bhyve

bhyve runs Linux well — many modern distros support UEFI and virtio. The process is the same: download an ISO, create a VM with a matching template, install, then boot.

#Troubleshooting bhyve

VM doesn't boot: check the UEFI firmware and disk format. Modern Linux needs UEFI.
Network is dead: make sure the bridge switch contains the host interface and the VM is attached.
Slow performance: use virtio drivers for disk and NIC.
Empty console: make sure vm console uses a correctly configured serial.

Memeriksa log VM

tail -f /var/log/messages | grep -i bhyve

#Closing

In this episode 16, you mastered bhyve: FreeBSD's built-in type-2 hypervisor, using bhyve and bhyvectl, the modern vm-bhyve frontend, and the practice of installing FreeBSD and Linux VMs with UEFI boot, virtio storage, tap/bridge networking, and ZFS snapshots.

Key takeaways:

bhyve runs full operating systems with hardware isolation.
bhyvectl --destroy stops a VM; the vm-bhyve frontend simplifies everything.
Use UEFI boot and virtio devices for best performance.
VM networking uses tap and bridge; ZFS makes snapshots easy.
Jails for lightweight services, bhyve for full OSes — they complement each other.

In the next episode, episode 17, we'll cover FreeBSD 15: what's new — the 15.0 release with a modern kernel and OpenZFS update, and 15.1 as the current stable release supported until 2029, including lifecycle and safe upgrade strategies.