From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43474) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCLtT-0003rs-BJ for qemu-devel@nongnu.org; Mon, 26 Mar 2012 22:12:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SCLtR-0008Ti-FN for qemu-devel@nongnu.org; Mon, 26 Mar 2012 22:12:18 -0400 Received: from 50-56-35-84.static.cloud-ips.com ([50.56.35.84]:37858 helo=mail.hallyn.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCLtR-0008TX-As for qemu-devel@nongnu.org; Mon, 26 Mar 2012 22:12:17 -0400 Date: Tue, 27 Mar 2012 02:12:33 +0000 From: "Serge E. Hallyn" Message-ID: <20120327021233.GA18109@mail.hallyn.com> References: <20120326151340.GA25460@mail.hallyn.com> <4F70C722.9040902@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F70C722.9040902@codemonkey.ws> Subject: Re: [Qemu-devel] [PATCH 1/1] If user doesn't specify a uuid, generate a random one List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: qemu-devel@nongnu.org, "Serge E. Hallyn" Quoting Anthony Liguori (anthony@codemonkey.ws): > On 03/26/2012 10:13 AM, Serge E. Hallyn wrote: > >Currently, if the user doesn't pass a uuid, the system uuid is set to > >all zeros. This patch generates a random one instead. > > > >Is there a reason to prefer all zeros? If not, can a patch like this > >one be applied? > > > >Signed-off-by: Serge Hallyn > > The other hypervisors don't have a concept of a transient guest like QEMU does. True, and I generally don't like arguments of the form "but (some other) does it like this," but... > There is no state preserved between invocations of QEMU. Right, and I really don't know how many users (besides me) run kvm by hand, as opposed to using libvirt or testdrive. Perhaps testdrive should be extended. > Setting a random UUID doesn't seem like the right answer to me as it > would potentially break Windows VMs. > > Perhaps if the DMI UUID isn't set, you could look at the root filesystem's UUID? Interesting idea. I don't know enough to know at which point in the code qemu would know that, but I can take a look. > Not all platforms have a notion of platform UUID so as Ubuntu > supports more architectures, this problem would have to be dealt > with eventually. So it sounds like in this form certainly it's nacked :) thanks, -serge