From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: XEN Proposal Date: Fri, 12 Dec 2008 07:09:22 +0100 Message-ID: <49420012.4030000@fujitsu-siemens.com> References: <573BF77E-A544-448E-BEBB-1DE3503B77CF@tycho.ncsc.mil> <4940B1D2.4060706@fujitsu-siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: George Dunlap Cc: Chris , "Tian, Kevin" , xen-devel@lists.xensource.com, Keir Fraser List-Id: xen-devel@lists.xenproject.org George Dunlap wrote: > On Thu, Dec 11, 2008 at 6:23 AM, Juergen Gross > wrote: >>> The software prices for BS2000 will be still related to the machine power. >> But often customers need only a small portion of the complete x86 machine >> power for BS2000, so we added a license scheme to limit the power available >> to BS2000 by pinning the domains with BS2000 to a subset of cpus. > > OK, so... you sell software, and the cost of it depends on how > powerful a machine you run it on. But most people don't need even one > full core's worth of power. You want to be able to charge people who > need a full core of processing power one price, and charge people who > need only say, 20%, less? So to artificially limit the power > available to a given instance, you pin all instances to some subset of > cpus? More or less. But the processors of our servers are 6-core. A customer might want to pay for only some cores of power. > > I presume then, that there are multiple instances, and people pay for > how many cores they can use total...? And that your customers > generally have other things running on the server as well. Correct. > > It seems like what you really want is to cap the number of credits the > VMs can get, and then take them offline when their credits go negative > (instead of competing for resources in a "best-effort" fashion). :-) In theory, yes. But if a customer has a license for the power of 3 cores for BS2000, he should be able to run for example 4 BS2000 domains which must not consume more power in sum, but if 3 domains are more or less idle, the remaining domain could take all 3 cores. I don't think this is an easy job with caps. > > However, it does seem like being able to partition up a Xen server > into "pools" of cpu resources, each with its own scheduler, that don't > compete with each other, might be generally useful. It should be > relatively straightforward to slide in under the current scheduler > architecture, without having to change much in the schedulers > themselves. That's how I'd prefer it done, if possible: a clean layer > underneath a scheduler. That is the direction I would go. Juergen -- Juergen Gross Principal Developer IP SW OS6 Telephone: +49 (0) 89 636 47950 Fujitsu Siemens Computers e-mail: juergen.gross@fujitsu-siemens.com Otto-Hahn-Ring 6 Internet: www.fujitsu-siemens.com D-81739 Muenchen Company details: www.fujitsu-siemens.com/imprint.html