From owner-freebsd-questions@FreeBSD.ORG Wed Dec 8 20:24:37 2010 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 91F851065673 for ; Wed, 8 Dec 2010 20:24:37 +0000 (UTC) (envelope-from syshackmin@gmail.com) Received: from mail-bw0-f49.google.com (mail-bw0-f49.google.com [209.85.214.49]) by mx1.freebsd.org (Postfix) with ESMTP id 230FE8FC08 for ; Wed, 8 Dec 2010 20:24:36 +0000 (UTC) Received: by bwz5 with SMTP id 5so1840357bwz.8 for ; Wed, 08 Dec 2010 12:24:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:date:message-id :subject:from:to:content-type; bh=Iml+McYRadN/PjirPIE9ybpg0WV3p3EPc0ZkERwe1iA=; b=UcyZK0pYOP9TlA3s64I62qM5bm9y+AS2vvq2ou90pvJSCZ3Iw6znW/Vjsr5E1z3BJA r8IcaYZgtze7/DpFT1CC/hIUO6y6/oYB8/fWwLCSD+awdmpzGo85a6ZLzSmqYlA92zVa bxa8yfrq6pYWUCJ4f5ENpqDvUxRL9kBqZF5is= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=YxvxbubKL+vcYBmTCEsY1l98G7TL/Antf5d8gPGg031i6z+JLARmzD24Xzilc3Jn3x VrTkD18fj0hzh0998YgjVT69Em+S55FixA8Fh2hin1PQmy7UKWo87eWDot7GY8xK/1tL 1RbeE3SF1qt+/FApTdug0czXH0r4/q6NgFcLE= MIME-Version: 1.0 Received: by 10.204.74.69 with SMTP id t5mr2397655bkj.190.1291838468951; Wed, 08 Dec 2010 12:01:08 -0800 (PST) Received: by 10.204.56.135 with HTTP; Wed, 8 Dec 2010 12:01:08 -0800 (PST) Date: Wed, 8 Dec 2010 15:01:08 -0500 Message-ID: From: Dave Cundiff To: questions@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Cc: Subject: Terrible Clock Skew X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Dec 2010 20:24:37 -0000 Hi everyone, I posted this to the forum as well but figured I'd try here since the same people might not subscribe to both. I've been experiencing some terrible clock skew and just can't figure it out. By terrible I mean I'm losing 30 minutes a day. The loss only occurs when I bring the system under heavy load. The load is multiple Rsync backups to a ZFS pool(with gzip compression) backed by a 16 disk Raid50. I'm using a hardware Raid controller for battery backed write caching. Mobo: Supermicro X8DTL CPU: Dual Intel 5620 quad cores Raid: Areca 1620 I have ntp enabled but the skew happens to fast and it stops trying. I've tried a bunch of stuff from the various lists. I tried all my clock sources. TSC(-100) HPET(900) ACPI-fast(1000) i8254(0). I tried changing the kern.hz flag lower. I also tried disabling the enhanced speed step feature of this chip as per the FAQ on the site. Nothing works. Currently I'm defaults except the following settings. EIST Disabled in BIOS kern.hz="100" kern.timecounter.hardware=i8254 Is there anything else I could do to debug this? I can't really blame the hardware because I have these same boards/chips running in Linux with no clock issues. -- Dave Cundiff System Administrator A2Hosting, Inc http://www.a2hosting.com