From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:53561) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QoGSZ-0001pk-SZ for qemu-devel@nongnu.org; Tue, 02 Aug 2011 11:00:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QoGSU-0007NG-Sh for qemu-devel@nongnu.org; Tue, 02 Aug 2011 11:00:43 -0400 Received: from mail-pz0-f43.google.com ([209.85.210.43]:42218) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QoGSU-0007N6-KU for qemu-devel@nongnu.org; Tue, 02 Aug 2011 11:00:38 -0400 Received: by pzk1 with SMTP id 1so14013568pzk.30 for ; Tue, 02 Aug 2011 08:00:37 -0700 (PDT) Message-ID: <4E381111.5080702@codemonkey.ws> Date: Tue, 02 Aug 2011 10:00:33 -0500 From: Anthony Liguori MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3] XBZRLE delta for live migration of large memory apps List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Kevin Wolf , Stefan Hajnoczi , "Shribman, Aidan" , qemu-devel Developers On 08/02/2011 09:01 AM, Alexander Graf wrote: > > On 02.08.2011, at 15:45, Shribman, Aidan wrote: > >> Subject: [PATCH v3] XBZRLE delta for live migration of large memory apps >> From: Aidan Shribman >> >> By using XBZRLE (Xor Binary Zero Run-Length-Encoding) we can reduce VM downtime >> and total live-migration time for VMs running memory write intensive workloads >> typical of large enterprise applications such as SAP ERP Systems, and generally >> speaking for representative of any application with a sparse memory update pattern. >> >> On the sender side XBZRLE is used as a compact delta encoding of page updates, >> retrieving the old page content from an LRU cache (default size of 64 MB). The >> receiving side uses the existing page content and XBZRLE to decode the new page >> content. >> >> Work was originally based on research results published VEE 2011: Evaluation of >> Delta Compression Techniques for Efficient Live Migration of Large Virtual >> Machines by Benoit, Svard, Tordsson and Elmroth. Additionally the delta encoder >> XBRLE was improved further using XBZRLE instead. >> >> XBZRLE has a sustained bandwidth of 1.5-2.2 GB/s for typical workloads making it >> ideal for in-line, real-time encoding such as is needed for live-migration. How does this compare to just doing gzip compression for the same workload? Regards, Anthony Liguori