From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [User question] Huge buffer size on KVM host Date: Wed, 15 Aug 2012 15:57:16 +0300 Message-ID: <502B9CAC.3020705@redhat.com> References: <502B5877.1080901@digitalmedics.de> <502B883D.5080402@redhat.com> <4061CC51-5F7E-4C94-AC5E-EE857BCA412C@digitalmedics.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Martin Wawro Return-path: Received: from mx1.redhat.com ([209.132.183.28]:22209 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754337Ab2HOM5Z (ORCPT ); Wed, 15 Aug 2012 08:57:25 -0400 In-Reply-To: <4061CC51-5F7E-4C94-AC5E-EE857BCA412C@digitalmedics.de> Sender: kvm-owner@vger.kernel.org List-ID: On 08/15/2012 03:05 PM, Martin Wawro wrote: > > On Aug 15, 2012, at 1:30 PM, Avi Kivity wrote: > >>> We have noticed a strange thing in one of our setups which uses KVM for >>> virtualization. >>> The size of the buffer cache turns out to be rather large >>> [,,,] >>> >> >> How is you storage set up? Files (which format?) or logical volumes? >> what's the cache= setting? > > We are using logical volumes and the cache is set to 'none'. Strange, that should work without any buffering. What the contents of /sys/block/sda/queue/hw_sector_size and /sys/block/sda/queue/logical_block_size ? Replace sda by the disk underlying your physical volume. -- error compiling committee.c: too many arguments to function