From owner-freebsd-virtualization@freebsd.org Mon Jan 22 20:02:57 2018 Return-Path: Delivered-To: freebsd-virtualization@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A1041ED3012 for ; Mon, 22 Jan 2018 20:02:57 +0000 (UTC) (envelope-from SRS0=8YYm=ER=quip.cz=000.fbsd@elsa.codelab.cz) Received: from elsa.codelab.cz (elsa.codelab.cz [94.124.105.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 65F796BFF9 for ; Mon, 22 Jan 2018 20:02:57 +0000 (UTC) (envelope-from SRS0=8YYm=ER=quip.cz=000.fbsd@elsa.codelab.cz) Received: from elsa.codelab.cz (localhost [127.0.0.1]) by elsa.codelab.cz (Postfix) with ESMTP id 9BF2328416; Mon, 22 Jan 2018 21:02:53 +0100 (CET) Received: from illbsd.quip.test (ip-86-49-16-209.net.upcbroadband.cz [86.49.16.209]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by elsa.codelab.cz (Postfix) with ESMTPSA id E8B7828411; Mon, 22 Jan 2018 21:02:51 +0100 (CET) Subject: Re: syncing bhyve instances To: tech-lists , freebsd-virtualization@freebsd.org References: <5A66137D.5090608@redbarn.org> From: Miroslav Lachman <000.fbsd@quip.cz> Message-ID: Date: Mon, 22 Jan 2018 21:02:51 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Firefox/52.0 SeaMonkey/2.49.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Jan 2018 20:02:57 -0000 tech-lists wrote on 2018/01/22 20:47: > On 22/01/2018 16:38, Paul Vixie wrote: >> for live sync you'll have to run software inside the guest that knows >> how to properly freeze state. for example if there's a live database of >> any kind you'll want it to be in its quiet state before you sync from >> it. in those situations, i do use rsync. > > Yeah, thought it might be this. Sorry I wasn't more clear initially > about the use case. > > Basically, the production server is in a datacentre and the reserve > server is on a very fast vdsl service. The reason for the reserve server > is, if the production server fails then I swap DNS to point at the > reserved server and the guests on it without interruption of service. > All guests are running databases (mysql) though they aren't especially > busy. So I guess the best bet would be mysql replication for the > databases and rsync for everything except mysql? Forget about uninterrupted services. Even if you have very short times on DNS you will have downtime in minutes until old DNS entries expired. If you need "almost real-time replication" then you definitely need both ends online and do MySQL replication (with all its own problems). And some kind of rsync synchronisation as you said. Miroslav Lachman