From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60956) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bQCwk-0003Et-TP for qemu-devel@nongnu.org; Thu, 21 Jul 2016 08:19:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bQCwh-0008Do-6y for qemu-devel@nongnu.org; Thu, 21 Jul 2016 08:19:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40852) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bQCwh-0008Dj-1A for qemu-devel@nongnu.org; Thu, 21 Jul 2016 08:19:19 -0400 Date: Thu, 21 Jul 2016 13:19:14 +0100 From: "Daniel P. Berrange" Message-ID: <20160721121914.GG13528@redhat.com> Reply-To: "Daniel P. Berrange" References: <1469077560-20620-1-git-send-email-zhang.zhanghailiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1469077560-20620-1-git-send-email-zhang.zhanghailiang@huawei.com> Subject: Re: [Qemu-devel] [RFC PATCH 0/2] Migration: support working on file:url List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: zhanghailiang Cc: qemu-devel@nongnu.org, amit.shah@redhat.com, peter.huangpeng@huawei.com, dgilbert@redhat.com, quintela@redhat.com On Thu, Jul 21, 2016 at 01:05:58PM +0800, zhanghailiang wrote: > It is more simple to use file:url to migrate VM into file. > Besides, it will be used in memory snapshot. NB, you can already migrate into a file "exec:/bin/cat > /path/to/file" and likewise qemu -incoming "exec:/bin/cat /path/to/file" This avoids the problem with POSIX I/O on plain files not actually supporting O_NONBLOCK in any sensible manner, which your file: suggestion suffers from. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|