From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oren Laadan Subject: Re: [Ksummit-2010-discuss] checkpoint-restart: naked patch Date: Mon, 08 Nov 2010 14:34:24 -0500 Message-ID: <4CD850C0.7020609@cs.columbia.edu> References: <20101104164401.GC10656@sundance.ccs.neu.edu> <4CD3CE29.2010105@kernel.org> <4CD5DCE3.3000109@cs.columbia.edu> <20101107194222.GG31077@sundance.ccs.neu.edu> <4CD71A6B.3020905@cs.columbia.edu> <20101107230516.GJ31077@sundance.ccs.neu.edu> <4CD774CA.8030004@cs.columbia.edu> <20101108162630.GN31077@sundance.ccs.neu.edu> <4CD83DF4.4080009@cs.columbia.edu> <20101108183701.GA20262@sundance.ccs.neu.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20101108183701.GA20262@sundance.ccs.neu.edu> Sender: linux-kernel-owner@vger.kernel.org To: Gene Cooperman Cc: Kapil Arya , Tejun Heo , linux-kernel@vger.kernel.org, hch@lst.de, Linux Containers List-Id: containers.vger.kernel.org On 11/08/2010 01:37 PM, Gene Cooperman wrote: > Thanks for the careful response, Oren. For others who read this, > one could interpret Oren's rapid post as criticizing the work of > Andres Lagar Cavilla. I'm sure that this was not Oren's intention. > Please read below for a brief clarification of the novelty of SnowFlock. Err... yes, that was careless of me. I was too focused on getting the thread back to track. Thanks for pointing out. >>> about live migration, have you also looked at the work of >>> Andres Lagar Caviilla on SnowFlock? >>> http://andres.lagarcavilla.com/publications/LagarCavillaEurosys09.pdf >>> He does live migration of entire virtual machines, again with very >>> small delay. Of course, the issue for any type of live migration is that >>> if the rate of dirtying pages is very high (e.g. HPC), then there is >>> still a delay or slow response, due to page faults to a remote host. >> >> VMware, Xen and KVM already do live migration. However, VMs >> are a separate beast. > > I absolutely agree with your point that live migration of > applications is a different beast, and technically very novel. > Since I know Andres Lagar Cavilla personally, I also feel obligated > to comment why SnowFlock truly is novel in the VM space. First, as Andres > writes: > "SnowFlock is an open-source project [SnowFlock] built on the Xen 3.0.3 > VMM [Barham 2003]." > In the abstract, Andres points out one of the major points of novelty: > "To evaluate SnowFlock, we focus on the demanding > scenario of services requiring on-the-fly creation of hundreds > of parallel workers in order to solve computationallyintensive > queries in seconds." > We must be careful that we don't destroy someone's reputation without > a careful study of their work. Yes, it's really nice work - I saw it when I visited there. (Coincidentally the post-copy idea with Xen appeared also in VEE 09 briefly before). Oren.