---
name: "bhyveload"
section: "8"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/bhyveload"
---

# bhyveload(8)

load a FreeBSD guest inside a bhyve virtual machine

## NAME

**bhyveload** – load a FreeBSD guest inside a bhyve virtual machine

## SYNOPSIS

**bhyveload** \[**-C**\] \[**-S**\] \[**-c** *cons-dev*\] \[**-d** *disk-path*\] \[**-e** *name=value*\] \[**-h** *host-path*\] \[**-l** *os-loader*\] \[**-m** *memsize*\[*K\|k\|M\|m\|G\|g\|T\|t*\]\] *vmname*

## DESCRIPTION

**bhyveload** is used to load a FreeBSD guest inside a [bhyve(4)](/bhyve/4.md) virtual machine.

**bhyveload** is based on [loader(8)](/loader/8.md) and will present an interface identical to the FreeBSD loader on the user's terminal. This behavior can be changed by specifying a different OS loader.

The virtual machine is identified as *vmname* and will be created if it does not already exist.

## OPTIONS

The following options are available:

- **-c** *cons-dev*

  *cons-dev* is a [tty(4)](/tty/4.md) device to use for **bhyveload** terminal I/O.

  The text string "stdio" is also accepted and selects the use of unbuffered standard I/O. This is the default value.

- **-d** *disk-path*

  The *disk-path* is the pathname of the guest's boot disk image.

- **-e** *name=value*

  Set the FreeBSD loader environment variable *name* to *value*.

  The option may be used more than once to set more than one environment variable.

- **-h** *host-path*

  The *host-path* is the directory at the top of the guest's boot filesystem.

- **-l** *os-loader*

  Specify a different OS loader. By default **bhyveload** will use */boot/userboot.so*, which presents a standard FreeBSD loader.

- **-m** *memsize*\[*K\|k\|M\|m\|G\|g\|T\|t*\]

  *memsize* is the amount of memory allocated to the guest.

  The *memsize* argument may be suffixed with one of **K**, **M**, **G** or **T** (either upper or lower case) to indicate a multiple of Kilobytes, Megabytes, Gigabytes or Terabytes respectively.

  *memsize* defaults to 256M.

- **-C**

  Include guest memory in the core file when **bhyveload** dumps core. This is intended for debugging an OS loader as it allows inspection of the guest memory.

- **-S**

  Wire guest memory.

## EXAMPLES

To create a virtual machine named *freebsd-vm* that boots off the ISO image */freebsd/release.iso* and has 1GB memory allocated to it:

```
bhyveload -m 1G -d /freebsd/release.iso freebsd-vm
```

To create a virtual machine named *test-vm* with 256MB of memory allocated, the guest root filesystem under the host directory */user/images/test* and terminal I/O sent to the [nmdm(4)](/nmdm/4.md) device */dev/nmdm1B*

```
bhyveload -m 256MB -h /usr/images/test -c /dev/nmdm1B test-vm
```

## SEE ALSO

[bhyve(4)](/bhyve/4.md), [nmdm(4)](/nmdm/4.md), [vmm(4)](/vmm/4.md), [bhyve(8)](/bhyve/8.md), [loader(8)](/loader/8.md)

## HISTORY

**bhyveload** first appeared in FreeBSD 10.0, and was developed at NetApp Inc.

## AUTHORS

**bhyveload** was developed by Neel Natu ⟨*neel@FreeBSD.org*⟩ at NetApp Inc with a lot of help from Doug Rabson ⟨*dfr@FreeBSD.org*⟩.

## BUGS

**bhyveload** can only load FreeBSD as a guest.

## SECURITY CONSIDERATIONS

Note that in some configurations, **bhyveload** will execute guest loader scripts in the context of the host machine. Note, however, that **bhyveload** will enter a [capsicum(4)](/capsicum/4.md) sandbox before it loads the *os-loader* or executes any loader scripts. On the host filesystem, the sandbox will only have access to the path specified by the **-h** flag, the contents of the */boot* directory if **-l** was not specified, and the chosen console device.

Note that the guest loader scripts are already subject to some limitations that are not relaxed simply because we are running in userland. For instance, any I/O on the loader's “host” device that can be done in loader scripts is limited to the interface that **bhyveload** provides, which itself will restrict paths that can be touched to those within a specified **-h** directory, if any. Access to files within */boot* inside the sandbox would require arbitrary code execution in userboot, and userboot is usually provided by the host machine rather than anything that is a part of the guest image. All access to the **-h** directory as well as */boot* is strictly read-only in the sandbox.