From owner-freebsd-virtualization@freebsd.org Mon Jan 22 16:38:30 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 25F56EC9777 for ; Mon, 22 Jan 2018 16:38:30 +0000 (UTC) (envelope-from paul@redbarn.org) Received: from family.redbarn.org (family.redbarn.org [IPv6:2001:559:8000:cd::5]) (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 1609383A9E for ; Mon, 22 Jan 2018 16:38:29 +0000 (UTC) (envelope-from paul@redbarn.org) Received: from [IPv6:2001:559:8000:c9:25:18f3:ab89:c46d] (unknown [IPv6:2001:559:8000:c9:25:18f3:ab89:c46d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by family.redbarn.org (Postfix) with ESMTPSA id 0FF7D7594C for ; Mon, 22 Jan 2018 16:38:23 +0000 (UTC) Message-ID: <5A66137D.5090608@redbarn.org> Date: Mon, 22 Jan 2018 08:38:21 -0800 From: Paul Vixie User-Agent: Postbox 5.0.22 (Windows/20171208) MIME-Version: 1.0 To: freebsd-virtualization@freebsd.org Subject: Re: syncing bhyve instances References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; 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 16:38:30 -0000 i've used zfs for this, but i have to shut the guest down to do it. i'm using zvols for my guest system disks, so it's shut the guest down (maybe just to single-user mode) make a zfs checkpoint start the guest back up zfs send the checkpoint this also assumes that the sync-destination is a cold spare, sitting in its shutdown state until needed. 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. bhyve could conceivably offer a feature to export the guest RAM, and with a little page-stealing, this could be made into an incremental sync feed. but i predict it would be enormous in size for any non-trivial guest.