Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756858AbZJLO0j (ORCPT ); Mon, 12 Oct 2009 10:26:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756828AbZJLO0i (ORCPT ); Mon, 12 Oct 2009 10:26:38 -0400 Received: from casper.infradead.org ([85.118.1.10]:37164 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756769AbZJLO0h (ORCPT ); Mon, 12 Oct 2009 10:26:37 -0400 Date: Mon, 12 Oct 2009 07:26:42 -0700 From: Arjan van de Ven To: Christian Pernegger Cc: linux-kernel@vger.kernel.org Subject: Re: *Really* bad I/O latency with md raid5+dm-crypt+lvm Message-ID: <20091012072642.3a06a271@infradead.org> In-Reply-To: References: Organization: Intel X-Mailer: Claws Mail 3.7.2 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 824 Lines: 19 On Mon, 12 Oct 2009 16:01:58 +0200 Christian Pernegger wrote: > [Please keep me CCed as I'm not subscribed to LKML] > > Summary: I was hoping to use a layered storage setup, namely lvm on > dm-crypt on md raid5 for a new box I'm setting up, but that isn't > looking so good since a single heavyish writer will monopolise any and > all I/O on the "device". F. ex. while cp'ing a few GB of data from an > external disk to the array it takes ~10sec to run ls and ~2min to > start aptitude. Clueless attempts at a diagnosis below. have you ran latencytop ? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/