From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wido den Hollander Subject: Re: Why only support odd number monitors in ceph cluster? Date: Fri, 23 Dec 2011 10:34:11 +0100 Message-ID: <4EF44B13.80301@widodh.nl> References: <8512670932FB654F81AF0FEF1BE6D49DABFBE6@WHQBEMAIL1.whq.wistron> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp02.mail.pcextreme.nl ([109.72.87.138]:35451 "EHLO smtp02.mail.pcextreme.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754042Ab1LWJdz (ORCPT ); Fri, 23 Dec 2011 04:33:55 -0500 In-Reply-To: <8512670932FB654F81AF0FEF1BE6D49DABFBE6@WHQBEMAIL1.whq.wistron> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Eric_YH_Chen@wistron.com Cc: ceph-devel@vger.kernel.org, Chris_YT_Huang@wistron.com, Alex_KT_Lin@wistron.com Hi, On 12/23/2011 08:21 AM, Eric_YH_Chen@wistron.com wrote: > Hi, all: > > I am curious about why ceph cluster only support odd number monitors. It doesn't only support a odd number. A even number of monitors works in theory, but it's recommended to use a odd number to get a majority. > > If we lose 1 monitor (becomes odd number), You shouldn't look to the number of online monitors, but to the number of monitors in your monmap. That should be a odd number. Wido > > would it cause any problem if we do not handle this situation in short time? > > Thanks! > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html