From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:34426) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RNnFk-0005XM-NE for qemu-devel@nongnu.org; Tue, 08 Nov 2011 10:06:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RNnFi-000588-Iy for qemu-devel@nongnu.org; Tue, 08 Nov 2011 10:06:20 -0500 Received: from fmmailgate03.web.de ([217.72.192.234]:51839) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RNnFi-00057q-5f for qemu-devel@nongnu.org; Tue, 08 Nov 2011 10:06:18 -0500 Received: from moweb001.kundenserver.de (moweb001.kundenserver.de [172.19.20.114]) by fmmailgate03.web.de (Postfix) with ESMTP id 3FC541A9BE1D0 for ; Tue, 8 Nov 2011 16:04:33 +0100 (CET) Message-ID: <4EB944FD.7030007@web.de> Date: Tue, 08 Nov 2011 16:04:29 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <1320543320-32728-1-git-send-email-agraf@suse.de> <4EB93FA4.8020800@redhat.com> <20111108145257.GA10846@infradead.org> In-Reply-To: <20111108145257.GA10846@infradead.org> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigC60E77515C186E33A408C163" Subject: Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christoph Hellwig Cc: Blue Swirl , "kvm@vger.kernel.org list" , qemu-devel Developers , "linux-kernel@vger.kernel.org List" , Alexander Graf , Pekka Enberg , Avi Kivity , Am?rico Wang , Ingo Molnar , Linus Torvalds , "Aneesh Kumar K.V" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigC60E77515C186E33A408C163 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2011-11-08 15:52, Christoph Hellwig wrote: > 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=3D/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). >=20 > 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. >=20 > 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.= I thought about this while hacking a slide on this topic: It's clumsy (compared to -snapshot - my favorite one as well), but you could use some snapshot on the host fs. Or a union fs (if we had an official one) with the write layer directed to some tmpfs area. But what we likely rather want (as it would work without privileges) is built-in write redirection for virtfs. Not an expert on this, but I guess that will have to solve the same problems an in-kernel union fs solution faces, no? Jan --------------enigC60E77515C186E33A408C163 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk65RP0ACgkQitSsb3rl5xQXBgCeOpYarFxnzImk5wYcpAYN46rh 0n8AniTaK8cXEu05DI00u8sejkZfHnXO =K5tx -----END PGP SIGNATURE----- --------------enigC60E77515C186E33A408C163--