From owner-freebsd-xen@FreeBSD.ORG Sun Jan 2 12:20:12 2011 Return-Path: Delivered-To: freebsd-xen@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EB580106566C for ; Sun, 2 Jan 2011 12:20:12 +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 BF9CC8FC19 for ; Sun, 2 Jan 2011 12:20:12 +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 p02CKCF2041382 for ; Sun, 2 Jan 2011 12:20:12 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id p02CKCg1041380; Sun, 2 Jan 2011 12:20:12 GMT (envelope-from gnats) Date: Sun, 2 Jan 2011 12:20:12 GMT Message-Id: <201101021220.p02CKCg1041380@freefall.freebsd.org> To: freebsd-xen@FreeBSD.org From: Greg Holmberg Cc: Subject: Re: kern/153620: Xen guest system clock drifts in AWS EC2 (FreeBSD 9.0-CURRENT i386 T1-micro) X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Greg Holmberg List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 02 Jan 2011 12:20:13 -0000 The following reply was made to PR kern/153620; it has been noted by GNATS. From: Greg Holmberg To: bug-followup@FreeBSD.org Cc: Subject: Re: kern/153620: Xen guest system clock drifts in AWS EC2 (FreeBSD 9.0-CURRENT i386 T1-micro) Date: Sun, 2 Jan 2011 12:51:33 +0100 On Sun, Jan 02, 2011 at 03:16:52AM -0800, Colin Percival wrote: > > Can you tell me: > 1. Did the clock run ahead, or behind? The NTP adjustment is a positive number (see below). Does this mean the clock is running slow? > 2. Can you reproduce this? > Yes. In the existing AMI, I just reset the clock again. Since I filed the PR, it had drifted "offset 0.124360 sec". While writing this email, it has drifted another "offset 0.009534 sec". I will let it go without correction for a while now. > 3. Did the clock _drift_, or _jump_? > Good question. Based on a handful of invocations of ntpdate, I would say that it drifts. The offset is different each time. ... Regards, Greg