[libvirt-users] Can I run a KVM guest with a btrfs subvolume as file system?

[Thomas Koch]

Hi again,

I've read and thought a bit more. Is the following possible:

1. create a folder (say /virtroot) on the host that should hold the root 
filesystem for the virtual machine
2. pass /bin, /sbin, /usr, /lib and /lib64 and /virtroot to the guest via 
virtfs[1]. Only the latter is passed writable.
3. create an initrd for the guest with an fstab that mounts the above folders 
at the right locations.
4. start the virtual machine without storage attached and use -kernel to pass 
a kernel from the host system

[1] http://www.linux-kvm.org/page/9p_virtio

As a result I could have a very lightweight debian stable virtual machine to 
run untrusted applications.

Regards, Thomas Koch