From owner-freebsd-hackers@freebsd.org Wed Dec 23 18:42:08 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 E0DDBA4F7DA for ; Wed, 23 Dec 2015 18:42:07 +0000 (UTC) (envelope-from kraduk@gmail.com) 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 C69E61B67 for ; Wed, 23 Dec 2015 18:42:07 +0000 (UTC) (envelope-from kraduk@gmail.com) Received: by mailman.ysv.freebsd.org (Postfix) id C4D3FA4F7D9; Wed, 23 Dec 2015 18:42:07 +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 A988DA4F7D8 for ; Wed, 23 Dec 2015 18:42:07 +0000 (UTC) (envelope-from kraduk@gmail.com) Received: from mail-wm0-x231.google.com (mail-wm0-x231.google.com [IPv6:2a00:1450:400c:c09::231]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 33FE91B65 for ; Wed, 23 Dec 2015 18:42:07 +0000 (UTC) (envelope-from kraduk@gmail.com) Received: by mail-wm0-x231.google.com with SMTP id l126so156564604wml.1 for ; Wed, 23 Dec 2015 10:42:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=UPEmF3pToxdEAt0ULlojHqgbLKA+AzMEpjUV/fEfqmU=; b=Mr7BchPXLbPEDBnxI5tdmx8dPe8GCVtYKTCUU0ZfaBrvSymvPFhARWJom9yKNMdLHx GyXyAKHWI79U3R9YAIEoHIQCUVn8Uc17FdAH5l/Vfxcm7C2z6aPa06U+rWlipw/DNEG4 AW92sQAgTpwLUGAZncRXifo3rvM7BRSWAxllqAOjfYs/ozEAP8Od3VIKbNmDmux2EzwU INInPNNxFLIq0vXj0lCFlc0B239yGTra60h0zMU8UnVrpWSFZKOYoV/6PaIwYH6J05RI J762CBqOuzvUbTcfWr+ZTQQMDqr7EXST+lO25awE0dRGs2xRKIhT6i/vLWhRFlls1Nha n/JA== MIME-Version: 1.0 X-Received: by 10.194.117.5 with SMTP id ka5mr16979299wjb.20.1450896125405; Wed, 23 Dec 2015 10:42:05 -0800 (PST) Received: by 10.28.55.85 with HTTP; Wed, 23 Dec 2015 10:42:05 -0800 (PST) Received: by 10.28.55.85 with HTTP; Wed, 23 Dec 2015 10:42:05 -0800 (PST) In-Reply-To: <26557C02-C591-4232-BBD0-988B0EB89575@gid.co.uk> References: <20151223121445.GA85016@ozzmosis.com> <26557C02-C591-4232-BBD0-988B0EB89575@gid.co.uk> Date: Wed, 23 Dec 2015 18:42:05 +0000 Message-ID: Subject: Re: The minimum amount of memory needed to use ZFS. From: krad To: Bob Bishop Cc: andrew clarke , Stephen Hocking , hackers@freebsd.org X-Mailman-Approved-At: Wed, 23 Dec 2015 20:05:16 +0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.20 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 18:42:08 -0000 If you want something small and cheap you could look at a Celeron based Intel nuc or similar. I think I built mine for about =C2=A3150, it has an = ssd and 4gb or ram and runs zfs on root fine. It's basically a beefy router with inbuilt transparent web caching. It works well and is relatively low power for what I need. The pi and aurdino would be in a different league though in both senses of power On 23 Dec 2015 17:58, "Bob Bishop" wrote: > Hi, > > > On 23 Dec 2015, at 12:14, andrew clarke wrote: > > > > On Wed 2015-12-23 21:43:37 UTC+1100, Stephen Hocking ( > stephen.hocking@gmail.com) wrote: > > > >> Inspired by this article: > >> > http://arstechnica.com/information-technology/2015/12/rsync-net-zfs-repli= cation-to-the-cloud-is-finally-here-and-its-fast/ > >> > >> I am wondering about changing my offsite back strategy, which currentl= y > 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? > > > > I'm curious about this too. > > > > Currently I run a root-on-ZFS FreeBSD 10.2 amd64 system with 2 GB RAM > > that I use for offline backups. The ZFS pool consists of 2 x 1 TB > > drives in a mirror setup. I've never had FreeBSD run out of memory on > > that machine. > > > > I suggest you avoid using the deduplication feature of ZFS which from > > what I understands likes to chew through memory. > > > > I don't use ZFS snapshots on that machine, so can't speak about their > > memory usage. Perhaps it's fairly insignificant, though. > > > > An alternative might be to use something like rsnapshot, still on ZFS. > > > > You might get a bigger audience if you ask on the freebsd-questions > > list. > > > > Regards > > Andrew > > FWIW we have a backup box currently running 9.2 amd64 with 4GB RAM and a > ZFS mirror. We use rsync to transfer the data daily, and ZFS snapshots to > maintain a Time Machine-like structure (currently something over 150 > snapshots in play). We did have some instances of apparent memory > exhaustion until we limited vfs.zfs.arc_max to 2GB; that doesn=E2=80=99t = seem to > have affected performance. > > Deduplication seems like a very bad idea unless you have both a lot of > duplicated data and a serious shortage of disk. It needs a lot of RAM, > increasing over time. Depending on the hardware and the use case, > compression (which effectively only costs CPU) might be a better option. > > -- > Bob Bishop > rb@gid.co.uk > > > > > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org= "