From owner-freebsd-fs@FreeBSD.ORG Fri Aug 17 17:36:14 2007 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2558E16A419 for ; Fri, 17 Aug 2007 17:36:14 +0000 (UTC) (envelope-from anderson@freebsd.org) Received: from ns.trinitel.com (186.161.36.72.static.reverse.ltdomains.com [72.36.161.186]) by mx1.freebsd.org (Postfix) with ESMTP id ED80413C480 for ; Fri, 17 Aug 2007 17:36:13 +0000 (UTC) (envelope-from anderson@freebsd.org) Received: from proton.local (209-163-168-124.static.twtelecom.net [209.163.168.124]) (authenticated bits=0) by ns.trinitel.com (8.14.1/8.14.1) with ESMTP id l7HHaAIQ072732; Fri, 17 Aug 2007 12:36:10 -0500 (CDT) (envelope-from anderson@freebsd.org) Message-ID: <46C5DC8C.50106@freebsd.org> Date: Fri, 17 Aug 2007 12:36:12 -0500 From: Eric Anderson User-Agent: Thunderbird 2.0.0.6 (Macintosh/20070728) MIME-Version: 1.0 To: Martin Cracauer References: <20070817155741.GA6255@cons.org> In-Reply-To: <20070817155741.GA6255@cons.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-1.6 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.1.8 X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on ns.trinitel.com Cc: freebsd-fs@freebsd.org Subject: Re: Block device over network from Linux to FreeBSD X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Aug 2007 17:36:14 -0000 Martin Cracauer wrote: > All right, here's a question that'll make your IQ drop by 5 points > just from pondering it :-) > > What's the best way to provide, over the network, a block device on > harddrives that live on a Linux box and "export" them to a FreeBSD > machine? Aka I want a FreeBSD filesystem on harddrives that are > physically in a Linux box. > > Long story: > > My backup strategy is a FreeBSD filesystem with snapshots on a bunch > of harddrives that live on networked computers in the basement. All > these computers boot diskless or disky into a variety of OSes, usually > Linux or FreeBSD. It would be easy to just use ext2fs or another > filesystem supported by both, but I'd really like ufs2 snapshots. So > I need to access the disks in a box running Linux as a block device > from a machine running FreeBSD. When the machine having the physical > disks runs FreeBSD I want to access the same raw devices directly, of > course. > > The brute-force approach would be: > - ext2fs on disks > - files inside ext2fs for use via mdconfig (and ccd) > - then, depending on OSes booted, either: > - export via NFS and mdconfig on NFS mounts on remote FreeBSD machine > - direct FreeBSD mount (machine runs FreeBSD) > > Another alternative I see is VMware or if any of the free emulators > can boot FreeBSD on Linux and use the disks directly in the guest OS. > > Linux has a network layer for block devices: > http://www.it.uc3m.es/ptb/nbd/ . On first sight, it doesn't look too > exiting nor does it look straightforward to implement a client in > GEOM. It uses daemons on both ends, so failover will not exactly be > an improvement over NFS. At least with NFS you know that a lot of > other people depend on what you write being delivered eventually. > > Then there's ATA over Ethernet as an established protocol. > > Any other ideas? > > USB'ing the harddrives is not considered sportish :-) > > Martin iSCSI? Eric