From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx11.extmail.prod.ext.phx2.redhat.com [10.5.110.16]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id pAF7wNpV030147 for ; Tue, 15 Nov 2011 02:58:23 -0500 Received: from h01.hoster-ok.com (h01.hoster-ok.com [88.86.111.110]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id pAF7wLWO015404 for ; Tue, 15 Nov 2011 02:58:22 -0500 Received: from bubble-sam.sam-solutions.net (r01-ge0-SH.prague.vds-ok.com [88.86.98.3] (may be forged)) (authenticated as ) by h01.hoster-ok.com (8.14.3/8.14.3/HOSTER-OK) with ESMTP id pAF7wI9m000804 (using TLSv1/SSLv3 with cipher DHE-RSA-AES256-SHA (256 bits) verified NO) for ; Tue, 15 Nov 2011 08:58:19 +0100 Message-ID: <4EC21B9A.4080702@hoster-ok.com> Date: Tue, 15 Nov 2011 10:58:18 +0300 From: Vladislav Bogdanov MIME-Version: 1.0 References: <3D44B3DCE57399449CC1391C2AD6EC4C16EA8D76@ORSMSX101.amr.corp.intel.com> <4EBB93F0.8070901@hoster-ok.com> <3D44B3DCE57399449CC1391C2AD6EC4C16EB33A8@ORSMSX101.amr.corp.intel.com> In-Reply-To: <3D44B3DCE57399449CC1391C2AD6EC4C16EB33A8@ORSMSX101.amr.corp.intel.com> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] cLVM commands often taking a long time to execute Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-lvm@redhat.com 10.11.2011 19:16, Riches Jr, Robert M wrote: > Thank you, Vladislav, for the suggestion. That could potentially > help in cases where the nodes are CPU-bound, likely independent of > whether they are I/O-bound. Except filtering unneeded block devices. This greatly helps in IO-bound setups. > > Thanks, > > Robert Riches > > -----Original Message----- From: linux-lvm-bounces@redhat.com > [mailto:linux-lvm-bounces@redhat.com] On Behalf Of Vladislav > Bogdanov Sent: Thursday, November 10, 2011 1:06 AM To: > linux-lvm@redhat.com Subject: Re: [linux-lvm] cLVM commands often > taking a long time to execute > > 09.11.2011 03:06, Riches Jr, Robert M wrote: >> I'm running into some odd behavior from clustered LVM commands on a >> 3-node pacemaker-based cluster. When other processes on the nodes >> are doing somewhat heavy sequential I/O traffic, LVM commands such >> as lvs, pvs, vgs, lvdisplay, pvdisplay, and vgdisplay have widely >> variable, often very long execution times. The same LVM command >> done repetitively will have execution times varying from less than >> a second to 10-15 seconds, more rarely up to around 60 seconds. >> Other read-heavy commands such as find, wc, and sum have much less >> variability and much shorter tails in the distribution of their >> execution times. >> >> Is it known what causes the cLVM commands to be so slow at times? >> >> Perchance, are there known ways to get cLVM commands to be less >> slow? > > I use chrt -r 99 for them. And I also run clvmd the same way. But > this is much more about CPU load then IO load. Also, please make sure > that you correctly filter unneeded block devices from being > PV-suspects (filter clause in lvm.conf). > > Best, Vladislav > > _______________________________________________ linux-lvm mailing > list linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO > at http://tldp.org/HOWTO/LVM-HOWTO/ > > _______________________________________________ linux-lvm mailing > list linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO > at http://tldp.org/HOWTO/LVM-HOWTO/