From owner-freebsd-stable@FreeBSD.ORG Fri Nov 26 13:41:15 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 354D51065675 for ; Fri, 26 Nov 2010 13:41:15 +0000 (UTC) (envelope-from avg@freebsd.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 7EF858FC14 for ; Fri, 26 Nov 2010 13:41:14 +0000 (UTC) Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua [212.40.38.101]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id PAA25233; Fri, 26 Nov 2010 15:41:12 +0200 (EET) (envelope-from avg@freebsd.org) Message-ID: <4CEFB8F7.4080002@freebsd.org> Date: Fri, 26 Nov 2010 15:41:11 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.12) Gecko/20101029 Lightning/1.0b2 Thunderbird/3.1.6 MIME-Version: 1.0 To: Adam Vande More References: In-Reply-To: X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org Subject: Re: More IO identification problems X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Nov 2010 13:41:15 -0000 on 26/11/2010 08:05 Adam Vande More said the following: > As a follow-up, after applying both patches presented in this thread(FreeBSD > 8.2-PRERELEASE #5: Thu Nov 25 19:14:00 CST 2010), > > http://lists.freebsd.org/pipermail/freebsd-stable/2010-November/060298.html > > "top -m io" now displays much more info and is generally consistent with > gstat in that IO spikes occer around the same time. However, gstat and "top > -m io" are still not displaying any stats for 90%+ of my hard drive > indicator light blinks. Since the issue effects gstat as well, it doesn't > seem like it could be related to ZFS. When the system is basically idling, > the only consistent IO related entries are these; > > 6 root 15 0 1 12 0 13 20.00% > {l2arc_feed_threa} > 6 root 15 0 1 12 0 13 20.00% > {arc_reclaim_thre} > 6 root 15 0 1 12 0 13 20.00% {zvol > zoot/usr/ho} > 6 root 15 0 1 12 0 13 20.00% > {txg_thread_enter} > 6 root 15 0 1 12 0 13 20.00% > {txg_thread_enter} > > Entries like these occur like clockwork on 30 sec intervals. My theory here > is that since the ZVOL has UFS + SU, this is causing a sync? > > What I'm trying to diagnose is a much more frequent hard drive access which > occurs on approximately 2 sec intervals. I timed this by pinging localhost > and comparing the response to the blinks. It's very consistent although not > completely so as once in awhile the blink occurs every second. If I listen > carefully I can hear increased drive activity during many of these intervals > so the indicator light seems to be working correctly. > > If anyone has ideas or tests they'd like me to run, it would be appreciated. > Perhaps it's some external component? E.g. hald is known to perform some disk/media checks every two seconds. -- Andriy Gapon