alwaysInBeta Stable software is for the weak

Quick qemu (virtual machines made easy) date: 2014-09-20 23:21:50+00:00

This assumes that you already have an iso to install from. If you're just using a live CD, skip making a virtual hard drive and drop the "-hda" argument from booting the machine. If you can spare it, give the VM more RAM by increasing 256 to something higher

First, you need a hard drive image. Raw images are useful, but qcow2 is sparse, so it won't gobble a lot of space for a quick test machine.

qemu-img create -f qcow2 fbsd0.qcow2 5G

Then boot the VM from your iso with the hard drive attached:

qemu-system-i386 -cdrom ~/Downloads/FreeBSD-10.0-RELEASE-i386-bootonly.iso -hda fbsd0.qcow2 -boot d -net nic -net user -m 256 -localtime

Once you've installed your system, shut down and then start from the hard drive:

qemu-system-i386 -hda fbsd0.qcow2 -boot c -net nic -net user -m 256 -localtime

Most of this was based on except that I had to specify the disk format