From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50843) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aqGxK-0002UU-0z for qemu-devel@nongnu.org; Wed, 13 Apr 2016 05:19:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aqGxF-0004Nl-1P for qemu-devel@nongnu.org; Wed, 13 Apr 2016 05:19:25 -0400 Received: from proxmox.maurer-it.com ([94.136.31.133]:54673) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aqGxE-0004NI-Rd for qemu-devel@nongnu.org; Wed, 13 Apr 2016 05:19:20 -0400 Received: from proxmox.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox.maurer-it.com (Proxmox) with ESMTP id 81E27AD0905 for ; Wed, 13 Apr 2016 11:12:51 +0200 (CEST) References: From: Thomas Lamprecht Message-ID: <570E0D91.2020808@proxmox.com> Date: Wed, 13 Apr 2016 11:12:49 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] Qemu-kvm live migration modify List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org hi, this message would probably be better suited on the qemu-discuss list not the devel. comments inline. On 13.04.2016 09:43, Gilar Dwitresna wrote: > hi,=20 > I have done make implementation of qemu-kvm instalation for live > migration on ubuntu with sharing storage (NFS) configuration. > the qemu-kvm has been succeed for live migration with default algorithm > (guest without service), but if the guest run the service (streaming > server), the dirty pages rate are increase from 900 to 7000 pages, and > live migration can't succeed. >=20 > i have played run live migration with extended downtime 30 second, live > migration can be succees, consequenly the downtime come to increase. > My system use fast ethernet 100mbps for network bandwidth, 2 PC with ra= m That's really not fast but more like the lower limit, a guest which dirties page quickly can saturate the max 100Megabits/s / 8 =3D 12.5 megabyte/s line really quick. 1 Gb/s (=3D125 megabyte/s) would be an better option. > 8 GB for host, 1 PC RAM 4GB HDD 500 GB for NFS shared storage. Guest VM > configure with 2GB RAM HDD 100 GB, migrate from host A to host B. >=20 > From some reference, if the write rate to the memory pages in use by th= e > VM (here after referred to as the dirty page rate) is high compared wit= h > the cost of transferring the pages between the two hosts involved in th= e > process, (as dictated, among others, by the network bandwidth,) then > live migration may not be possible. >=20 With qemu 2.5 you have better autoconverge of live migration, see: http://wiki.qemu.org/Features/AutoconvergeLiveMigration Also post copy ram (introduced as experimental in qemu 2.5) would be an option, see http://wiki.qemu.org/Features/PostCopyLiveMigration cheers, Thomas > In the case with the high dirty pages, i run the live migration while > the guest run the streaming server with network bandwidth 100 mbps, the= n > the server can be migrated. >=20 > can i modify qemu-kvm live migration algorithm? and what should i do to > modify this algorithm that can be migrate while the VM Guest run the > servive (streaming server) without extended downtime? >=20 > Thanks. > Regards, Papandayan >=20