From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Mueller Subject: Re: "clocks not synchronized" warning message Date: Thu, 8 Jul 2010 15:04:42 +0000 (UTC) Message-ID: References: <1278598768.2253.18.camel@wido-laptop.pcextreme.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: Received: from lo.gmane.org ([80.91.229.12]:57697 "EHLO lo.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754475Ab0GHPEx (ORCPT ); Thu, 8 Jul 2010 11:04:53 -0400 Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1OWseg-0007Rl-M3 for ceph-devel@vger.kernel.org; Thu, 08 Jul 2010 17:04:50 +0200 Received: from cust.dyn.95-152-98-129.swisscomdata.ch ([95.152.98.129]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 08 Jul 2010 17:04:50 +0200 Received: from thomas by cust.dyn.95-152-98-129.swisscomdata.ch with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 08 Jul 2010 17:04:50 +0200 Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org Am Thu, 08 Jul 2010 07:53:00 -0700 schrieb Sage Weil: > On Thu, 8 Jul 2010, Thomas Mueller wrote: > >> Am Thu, 08 Jul 2010 16:19:28 +0200 schrieb Wido den Hollander: >> >> > Hi, >> > >> > I'm experiencing the same. The default "mon lease wiggle room" is set >> > t .001, which gives the messages in my setup. >> >> this is what I just found too - in unstable the default is now 0.010. >> with 0.5 the message was still there. with 1.0 it was away. >> >> I think 0.010 is still a bit small for a system not connected to a >> atomic clock? :) > > How about .5 seconds? We sync our machines to a local ntp server, so > the clocks get really close (sub-ms). I forget that NTP isn't so > accurate over a WAN. > > The issue is that the monitor leases and timeouts are something like 2 > seconds (so that failures/unavailability) are detected quickly, so the > tolerable clock drift can't get too close to that. > > sage ok, if this is the problem, then I would also recommend running an ntp daemon (not ntpdate) on every node. A running ntpd will manage the timesource to be in sync. If anyone likes to run an mds/mon on a VM I expect problems - virtualized clocksources are far less stable (my experience). - Thomas