From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alejandro Comisario Subject: kvm cpu usage allocation Date: Wed, 19 Feb 2014 18:42:56 -0300 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: kvm@vger.kernel.org Return-path: Received: from mail-qa0-f43.google.com ([209.85.216.43]:59453 "EHLO mail-qa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752515AbaBSVnR (ORCPT ); Wed, 19 Feb 2014 16:43:17 -0500 Received: by mail-qa0-f43.google.com with SMTP id o15so1608150qap.2 for ; Wed, 19 Feb 2014 13:43:16 -0800 (PST) Sender: kvm-owner@vger.kernel.org List-ID: Hi everyone. We are having a private cloud with more than 1000 phy servers. Each server has 128GB of RAM and 24 cores (2 heaxacores with HT enabled), but the amount of vms running on those servers versus the flavor (amount of CPU) made us use about 80 VCPUS. The questions are as follow. * is there a fine documentation of HOW kvm handles cpu allocation/pin per vm in an scenario like this one ? * is there also, a documentation that explains under a circumstance where a VM needs more processing power, how priority is managed ? * is there a way to define some kind of politics or rules to have specific cpu pinning for specific vms ? So, well ... any extensive information to understand how KVM behaves would be great! Thanks as allways! ---------- @lejandrito