Virtual Disks

When a guest is created from a template, a disk image is created for each disk specified in the template. If you would like to add disks to a guest after it has been created, you can either use the vm add command, or create the disk image then update the configuration file manually.

Below are some examples of supported disk configurations

Simple Sparse File

disk0_type="virtio-blk"
disk0_name="disk0.img"

Sparse ZVOL

Non sparse zvols are also supported by just specifying disk0_dev="zvol"

disk0_type="virtio-blk"
disk0_name="disk0"
disk0_dev="sparse-zvol"

Custom Disk

This allows you to specify a custom path to a disk image. The disk could be a sparse file, a ZVOL, or even a real disk under /dev/

disk0_type="virtio-blk"
disk0_name="/dev/ada10"
disk0_dev="custom"

Simple Sparse File With Options

disk0_type="virtio-blk"
disk0_name="disk0.img"
disk0_opts="nocache,direct"

Custom ZVOL disk

If you would like to attach an additional disk to an existing guest using a ZVOL, follow these instructions.

First of all, create a new ZVOL for the disk image. If you do not want the ZVOL to be sparse, remove the -s option.

# zfs create -sV 50G -o volmode=dev path/to/dataset/zvol

Then add this as an additional disk to your guest configuration file.

# vm configure myguest

disk1_name="/dev/zvol/path/to/dataset/zvol"
disk1_type="virtio-blk"
disk1_dev="custom"

VirtIO 9p share

This is a configuration example for sharing files/folders with a VM using VirtIO 9p.

First, add the following to the guest configuration file:

# vm configure myguest

disk1_type="virtio-9p"
disk1_name="sharename=/path/to/share" 
disk1_dev="custom"

Optionally, append ,ro to disk1_name to make it read-only.

On a FreeBSD guest, the 9p share can be mounted with the following command:

# mount -t 9p -o trans=virtio sharename /local/mount/point/of/share

Persistent configuration can be done with fstab(5):

sharename          /local/mount/point/of/share    9p      trans=virtio,rw 0 0