From owner-freebsd-fs@FreeBSD.ORG Wed Nov 5 15:41:54 2014 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 5A0AFBB5 for ; Wed, 5 Nov 2014 15:41:54 +0000 (UTC) Received: from mta1-filtered.netlife.no (mail.netlife.no [62.92.26.226]) by mx1.freebsd.org (Postfix) with ESMTP id 13FC1D32 for ; Wed, 5 Nov 2014 15:41:53 +0000 (UTC) Received: from amavis.netlife.no (unknown [10.115.1.11]) by mta1-filtered.netlife.no (Postfix) with ESMTP id 1057D1C9573 for ; Wed, 5 Nov 2014 16:36:12 +0100 (CET) X-Virus-Scanned: amavisd-new at netlife.no Received: from mta1-submission.netlife.no ([62.92.26.226]) by amavis.netlife.no (amavis.netlife.no [10.115.1.11]) (amavisd-new, port 10026) with ESMTP id siOdQLDlZaof for ; Wed, 5 Nov 2014 16:36:11 +0100 (CET) Received: from [10.0.0.41] (unknown [195.1.220.218]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: erik@tefre.com) by mta1-submission.netlife.no (Postfix) with ESMTPSA id D80EA1C956F for ; Wed, 5 Nov 2014 16:36:11 +0100 (CET) Message-ID: <545A43EB.7070603@tefre.com> Date: Wed, 05 Nov 2014 16:36:11 +0100 From: Erik Stian Tefre User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: freebsd-fs@freebsd.org Subject: Re: Differences in memory handling on systems with/out cache drives References: <5F9E965F5A80BC468BE5F40576769F099DF87F57@exchange2-1> <5F9E965F5A80BC468BE5F40576769F099DF87FBB@exchange2-1> In-Reply-To: <5F9E965F5A80BC468BE5F40576769F099DF87FBB@exchange2-1> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Nov 2014 15:41:54 -0000 On 05. nov. 2014 09:53, Karli Sjöberg wrote: > On Wed, 2014-11-05 at 08:44 +0000, Karli Sjöberg wrote: >> Hey all! >> >> Still investigating the intermittent lockups we are experiencing on our >> storage systems and have started to compare memory graphs from our >> Graphite monitoring system. What´s interesting about two of our systems >> is that they both have the same amount of RAM; 32 GB. But on one of >> them, I have "zpool remove"'d the cache drives from the pool and have >> been able to study how different their memory graphs now look like. >> >> Also worth noting is that the cache-less system nearly haven´t swapped >> at all (1112K) since the last stall 20 days ago, while the other system >> has swapped 78 MB during it´s 48 days of uptime. >> >> I´ve attached both screenshots from the two systems, with- and without >> cache drives, displaying a period of 12 hours. >> >> What´s most notable are the characteristic cuts that happen on the >> cache-less system when ZFS goes in and evicts blocks from ARC that shows >> as a decrease in "wired" and increase in "free", that just doesn´t >> happen/looks different in the system with cache drive configured in the >> pool. >> >> What´s your take on this? Are we hitting bug: 187594 perhaps? How can we >> know? Take a look at the recent thread on freebsd-stable@, subject "ARC size limit". Possibly related issues have been patched in stable/10, the mailing list thread includes a patch for releng/10.1. -- Erik