From owner-freebsd-bugs@FreeBSD.ORG Sun Jan 2 10:40:14 2011 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 49FBE1065673 for ; Sun, 2 Jan 2011 10:40:14 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 0CB0F8FC14 for ; Sun, 2 Jan 2011 10:40:14 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id p02AeD9L030301 for ; Sun, 2 Jan 2011 10:40:13 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id p02AeDOA030300; Sun, 2 Jan 2011 10:40:13 GMT (envelope-from gnats) Resent-Date: Sun, 2 Jan 2011 10:40:13 GMT Resent-Message-Id: <201101021040.p02AeDOA030300@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Greg Holmberg Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 63298106566B for ; Sun, 2 Jan 2011 10:33:34 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from red.freebsd.org (unknown [IPv6:2001:4f8:fff6::22]) by mx1.freebsd.org (Postfix) with ESMTP id 522968FC0A for ; Sun, 2 Jan 2011 10:33:34 +0000 (UTC) Received: from red.freebsd.org (localhost [127.0.0.1]) by red.freebsd.org (8.14.4/8.14.4) with ESMTP id p02AXYno070847 for ; Sun, 2 Jan 2011 10:33:34 GMT (envelope-from nobody@red.freebsd.org) Received: (from nobody@localhost) by red.freebsd.org (8.14.4/8.14.4/Submit) id p02AXYYJ070846; Sun, 2 Jan 2011 10:33:34 GMT (envelope-from nobody) Message-Id: <201101021033.p02AXYYJ070846@red.freebsd.org> Date: Sun, 2 Jan 2011 10:33:34 GMT From: Greg Holmberg To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: kern/153620: Xen guest system clock drifts in AWS EC2 (FreeBSD 9.0-CURRENT i386 T1-micro) X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 02 Jan 2011 10:40:14 -0000 >Number: 153620 >Category: kern >Synopsis: Xen guest system clock drifts in AWS EC2 (FreeBSD 9.0-CURRENT i386 T1-micro) >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Sun Jan 02 10:40:13 UTC 2011 >Closed-Date: >Last-Modified: >Originator: Greg Holmberg >Release: 9.0-CURRENT i386 >Organization: >Environment: FreeBSD domU-12-31-39-13-00-E9 9.0-CURRENT FreeBSD 9.0-CURRENT #88: Wed Dec 29 09:55:39 UTC 2010 root@chch.daemonology.net:/usr/obj/i386.i386/usr/src/sys/XEN i386 >Description: 9.0-CURRENT system running as AMI in Amazon EC2 cloud keeps poor time. System was under heavy load, repeatedly compiling packages to exercise memory allocation code. Clock in guest should be updated faithfully by the host. Clock in this AMI drifted 2200 seconds over 11 hours. >How-To-Repeat: >From Amazon AWS Console, start a FreeBSD instance. I used ami-a0fc0dc9, the most recent 9.0-CURRENT available on Dec 30, 2010. Wait a few hours. (Maybe use it heavily?) Compare the correct time from a good NTP source with the AMI system clock. >Fix: No known fix. (Didn't rtfs yet) Workaround: perhaps run ntpdate out of cron every twenty minutes? >Release-Note: >Audit-Trail: >Unformatted: