From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: RAM utilization issues Date: Thu, 12 Jan 2012 12:36:28 +0200 Message-ID: <4F0EB7AC.1050201@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm To: Jonathan Petersson Return-path: Received: from mx1.redhat.com ([209.132.183.28]:41858 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751562Ab2ALKgb (ORCPT ); Thu, 12 Jan 2012 05:36:31 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 01/12/2012 11:27 AM, Jonathan Petersson wrote: > Hi, > > Throughout the last few months we've been slowly migrating off our old > VMware installation to KVM, most of it has been successful and people > has been happy with the end-result. > > The new infrastructure obviously has a bit more of power which is > heavily utilized by the guests however compared to VMware the RAM > usage is way above what we've expected. > > In our VMware environment we operated at 24GB with ballooning and we > were able to maintain usage at around 90% without any swapping. > However with the new environment we've 24x3 GB och RAM and we're > seeing a 80% utilization across the board with the same amount of > guests. > > Please notice that we've both ballooning (on both the host and guest) > and KSM enabled, hugepages hasn't made any major difference so we've > chosen to disable this. If you've any input as to why we're seeing > this behavior or if it's expected we'd appreciate it. In addition to > this we're utilizing virtio_blk/net/pci/ring and vhost_net. > > Some data: > root@kvm01-01:~# grep -i balloon /boot/config-$(uname -r) > CONFIG_VMWARE_BALLOON=m > CONFIG_XEN_BALLOON=y > CONFIG_VIRTIO_BALLOON=y > What's the aggregate size of the guests (sum of all guest memory sizes)? How many guests? Are you in fact using the balloon? How? -- error compiling committee.c: too many arguments to function