From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60487) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aMDkJ-0000nX-1W for qemu-devel@nongnu.org; Thu, 21 Jan 2016 06:49:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aMDkF-00060a-Nz for qemu-devel@nongnu.org; Thu, 21 Jan 2016 06:49:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38814) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aMDkF-00060W-JA for qemu-devel@nongnu.org; Thu, 21 Jan 2016 06:49:43 -0500 Date: Thu, 21 Jan 2016 11:49:38 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20160121114937.GE2446@work-vm> References: <20160111195146.GC3084@work-vm> <4e396059b95b088f1cf3c6b6668160d5@alukardd.org> <20160112091937.GE2455@work-vm> <20160112100444.GG2455@work-vm> <20160112121139.GH2455@work-vm> <56997F94.3080706@redhat.com> <5a37c43587e03e8636a1ddfbfadd82f6@alukardd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5a37c43587e03e8636a1ddfbfadd82f6@alukardd.org> Subject: Re: [Qemu-devel] live migration between different qemu versions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Cc: Qemu devel * Alexey (alukardd@alukardd.org) wrote: > Hello, > > On 2016-01-16 02:24, Eric Blake wrote: > >On 01/12/2016 05:11 AM, Dr. David Alan Gilbert wrote: > > > >>>Tell me please right way to append zeros to "BIOS (ia32) ROM Ext. > >>>(137*512)" > >>>file? > >> > >>I'd use dd; something like: > >> dd if=/dev/zero bs=1 count=18944 >> theromfile > >>I think that should do it (203264-184320=18944) > > > >Or simpler: > > > >truncate --size=203264 theromfile > It's great! I have successfully did migration of VM from qemu 2.3.0 to qemu > 2.5.0. > > But when I try migrate to another side I got error: > qemu-system-x86_64: error while loading state for instance 0x0 of device > 'fw_cfg' > qemu-system-x86_64: load of migration failed: No such file or directory > > Is it possible to do this migration? Backwards migration doens't get much upstream testing; it looks like this is the same as: https://bugs.launchpad.net/qemu/+bug/1536487 Dave > Regards, > Alexey Mochkin. -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK