From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KNri3-0000no-UM for qemu-devel@nongnu.org; Tue, 29 Jul 2008 12:05:59 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KNri2-0000lw-Ae for qemu-devel@nongnu.org; Tue, 29 Jul 2008 12:05:59 -0400 Received: from [199.232.76.173] (port=37012 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KNri2-0000lm-5r for qemu-devel@nongnu.org; Tue, 29 Jul 2008 12:05:58 -0400 Received: from mail2.shareable.org ([80.68.89.115]:48806) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1KNri1-0002A6-Mt for qemu-devel@nongnu.org; Tue, 29 Jul 2008 12:05:57 -0400 Received: from jamie by mail2.shareable.org with local (Exim 4.63) (envelope-from ) id 1KNrhy-0005We-M6 for qemu-devel@nongnu.org; Tue, 29 Jul 2008 17:05:54 +0100 Date: Tue, 29 Jul 2008 17:05:54 +0100 From: Jamie Lokier Subject: Re: [Qemu-devel] [PATCH] qcow3 - arbitrary metadata Message-ID: <20080729160554.GC20980@shareable.org> References: <488E2752.7030008@codemonkey.ws> <20080729014939.GA27149@shareable.org> <488E8AE8.2060602@codemonkey.ws> <20080729064412.GA32582@shareable.org> <488F1D41.8010107@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <488F1D41.8010107@codemonkey.ws> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Anthony Liguori wrote: > >Does savevm snapshot the disk images too? > > Yes. Bah, annoying. > > I thought it was just the > >machine state. Does that mean non-qcow2 disks (e.g. raw files) are > >not snapshotted but qcow2 ones are, in the same VM? > > Raw files cannot be snapshotted. I don't want to :-) But I do want a consistent vM. According to QEMU docs, you can savevm if there's at least one qcow2 disk image. Does that mean it saves _just_ the state of that disk, or all the qcow2 disks which are attached (e.g. C: drive, D: drive, E: drive)? > >It's actually just the machine state I want to save. I want to use > >savevm to save the state of the VM before quitting, and loadvm to > >restart. Like suspend-to-RAM, but doesn't require the guest to > >cooperate. (Does suspend work anyway?) > > > If you do that, you risk having your disk in an improper state. If > there are any changes to the disk after you do your savevm, they will > not be present after you loadvm. This could cause very subtle data > corruption within your file system. The CPU is stopped before calling savevm And when restarting, the CPU is stopped with -S first, then loadvm, then the CPU is started. So no disk corruption - assuming QEMU doesn't keep dirty cached sectors in its process after savevm returns. -- Jamie