From owner-freebsd-fs@FreeBSD.ORG Mon May 10 18:26:02 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 7F21C106564A for ; Mon, 10 May 2010 18:26:02 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.cran.org.uk (muon.cran.org.uk [109.74.192.160]) by mx1.freebsd.org (Postfix) with ESMTP id 43C598FC15 for ; Mon, 10 May 2010 18:26:02 +0000 (UTC) Received: from muon.cran.org.uk (localhost [127.0.0.1]) by muon.cran.org.uk (Postfix) with ESMTP id D18E7C400D for ; Mon, 10 May 2010 18:10:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on muon.cran.org.uk X-Spam-Level: X-Spam-Status: No, score=-3.3 required=8.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.5 Received: from core.draftnet (87-194-158-129.bethere.co.uk [87.194.158.129]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by muon.cran.org.uk (Postfix) with ESMTPSA for ; Mon, 10 May 2010 18:10:31 +0000 (UTC) From: Bruce Cran To: freebsd-fs@freebsd.org Date: Mon, 10 May 2010 19:09:41 +0100 User-Agent: KMail/1.13.3 (FreeBSD/9.0-CURRENT; KDE/4.4.3; amd64; ; ) MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201005101909.41614.bruce@cran.org.uk> Subject: vm.kmem_size and ZFS on 9-CURRENT X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 May 2010 18:26:02 -0000 Hi, I recently converted my /home and /usr slices over to ZFS on my desktop running 9-CURRENT amd64 with 6GB RAM. In the process of copying data off /var to convert it too, I got the "kmem_map too small" panic, which led me to the thread at http://lists.freebsd.org/pipermail/freebsd- current/2010-April/016984.html which appears to conclude that the defaults even on -CURRENT aren't suitable and that vm.kmem_size needs tuned to be 2xRAM. Since I had followed the guide at http://wiki.freebsd.org/ZFSQuickStartGuide and http://wiki.freebsd.org/ZFSTuningGuide which didn't mention any tuning for amd64 with plenty of memory I had thought 9-CURRENT should "just work". Is the tuning of vm.kmem_size really needed? I've seen mention of an ARC tunable too - does it need changed? -- Bruce Cran