Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Christoph Hellwig]

On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote:
> On 11/06/2011 03:35 AM, Alexander Graf wrote:
> > To quickly get going, just execute the following as user:
> >
> >     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
> >
> > This will drop you into a shell on your rootfs.
> >
> 
> Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
> -virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
> detection is broken (patch posted).

Nevermind that running virtfs as a rootfs is a really dumb idea.  You
do now want to run a VM that has a rootfs that gets changed all the
time behind your back.

Running qemu -snapshot on the actual root block device is the only
safe way to reuse the host installation, although it gets a bit
complicated if people have multiple devices mounted into the namespace.