From owner-freebsd-hackers@freebsd.org Wed Dec 23 16:58:26 2015 Return-Path: Delivered-To: freebsd-hackers@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 0263DA4F1E6 for ; Wed, 23 Dec 2015 16:58:26 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id E51C91F29 for ; Wed, 23 Dec 2015 16:58:25 +0000 (UTC) (envelope-from ian@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id E3DB3A4F1E4; Wed, 23 Dec 2015 16:58:25 +0000 (UTC) Delivered-To: hackers@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 E3710A4F1E1 for ; Wed, 23 Dec 2015 16:58:25 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from erouter6.ore.mailhop.org (erouter6.ore.mailhop.org [54.187.213.119]) (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 C86B71F28 for ; Wed, 23 Dec 2015 16:58:25 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from ilsoft.org (unknown [73.34.117.227]) by outbound3.ore.mailhop.org (Halon Mail Gateway) with ESMTPSA; Wed, 23 Dec 2015 16:57:52 +0000 (UTC) Received: from rev (rev [172.22.42.240]) by ilsoft.org (8.14.9/8.14.9) with ESMTP id tBNGwHms003813; Wed, 23 Dec 2015 09:58:17 -0700 (MST) (envelope-from ian@freebsd.org) Message-ID: <1450889897.25138.190.camel@freebsd.org> Subject: Re: The minimum amount of memory needed to use ZFS. From: Ian Lepore To: Stephen Hocking , hackers@freebsd.org Date: Wed, 23 Dec 2015 09:58:17 -0700 In-Reply-To: References: Content-Type: text/plain; charset="us-ascii" X-Mailer: Evolution 3.16.5 FreeBSD GNOME Team Port Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Dec 2015 16:58:26 -0000 On Wed, 2015-12-23 at 21:43 +1100, Stephen Hocking wrote: > Hi all, > > Inspired by this article: > http://arstechnica.com/information-technology/2015/12/rsync-net-zfs-r > eplication-to-the-cloud-is-finally-here-and-its-fast/ > > I am wondering about changing my offsite back strategy, which > currently is > made up of a Raspberry Pi with an external 3TB drive sitting at my > brother's house, with periodic manual rsyncs. I'd like to change that > to > doing zfs replications. > > I want to use some of my ARM based hardware as the target for the ZFS > replication, owing to its low power usage. I have a few Cubiboxes > floating > around with around 2G of RAM, and a RPI2 or a Banana Pi with 1G. It'd > have > a UFS root on the SD card, and ZFS on the external drive. > > Any ideas? People have reported running arm systems using zfs in as little as 512MB (on a beaglebone), but it's a long way from "it boots" to "it's useful" and I have no idea if they were using the systems for anything other than proof of concept. I wouldn't consider using an rpi for even a moment. They're just too slow and the chipset too crippled to be useful as anything other than a toy, IMO. A Cubox (4 cores @1.2GHz, 2GB ram) should work fine. Right now your only storage option is a USB drive, (it has an eSata port but we don't have the ahci driver working on that platform yet). The freebsd-arm mailing list might get you replies from people who've been down this road themselves. -- Ian