From owner-freebsd-hackers@FreeBSD.ORG Mon Oct 6 23:57:16 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 550901065687 for ; Mon, 6 Oct 2008 23:57:16 +0000 (UTC) (envelope-from hartzell@alerce.com) Received: from merlin.alerce.com (merlin.alerce.com [64.62.142.94]) by mx1.freebsd.org (Postfix) with ESMTP id 3CE9D8FC15 for ; Mon, 6 Oct 2008 23:57:16 +0000 (UTC) (envelope-from hartzell@alerce.com) Received: from merlin.alerce.com (localhost [127.0.0.1]) by merlin.alerce.com (Postfix) with ESMTP id 9C70633C62; Mon, 6 Oct 2008 16:27:53 -0700 (PDT) Received: from merlin.alerce.com (localhost [127.0.0.1]) by merlin.alerce.com (Postfix) with ESMTP id 0710A33C5B; Mon, 6 Oct 2008 16:27:52 -0700 (PDT) From: George Hartzell MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18666.40675.636312.893786@almost.alerce.com> Date: Mon, 6 Oct 2008 16:27:31 -0700 To: Mike Meyer In-Reply-To: <20081006182558.708e4094@bhuda.mired.org> References: <48E9E1BB.6020908@ispro.net> <001AD718-D25B-421B-8B0F-CE71FA5A7CF0@gid.co.uk> <48EA21AE.80607@ispro.net> <20081006184934.04A645B4C@mail.bitblocks.com> <18666.33296.607120.889620@almost.alerce.com> <20081006182558.708e4094@bhuda.mired.org> X-Mailer: VM 7.19 under Emacs 22.1.50.1 X-Virus-Scanned: ClamAV using ClamSMTP X-Mailman-Approved-At: Tue, 07 Oct 2008 02:17:19 +0000 Cc: freebsd-hackers@freebsd.org, hartzell@alerce.com Subject: Re: continuous backup solution for FreeBSD X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: hartzell@alerce.com List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Oct 2008 23:57:16 -0000 Mike Meyer writes: > On Mon, 6 Oct 2008 14:24:32 -0700 > George Hartzell wrote: > > There were a couple of threads about using kqueue or other FreeBSD > > tools to build something like Mac OS X's Time Machine. R1soft's > > software sounds very similar. > > Time machine doesn't do continuous backups, it does them once an hour > or so. People have built similar systems on top of rsync; I did it on > top of zfs (turned out to be to fragile, though). You then just need a > spiffy GUI for wondering through the backups. On the other hand Time Machine does take advantage of a kernel based mechanism that watches file activity and does its best to take advantage of that information to avoid scanning the filesystem when it does a backup. That's the context of the message thread that I pointed to (again, for completeness) http://lists.freebsd.org/pipermail/freebsd-hackers/2008-June/024730.html The thread seemed relevant given the context of backup systems that watch filesystem io. g.