From owner-freebsd-hackers@freebsd.org Wed Dec 23 11:55:27 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 86119A4FA89 for ; Wed, 23 Dec 2015 11:55:27 +0000 (UTC) (envelope-from slw@zxy.spb.ru) 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 737EB1CE6 for ; Wed, 23 Dec 2015 11:55:27 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: by mailman.ysv.freebsd.org (Postfix) id 7103EA4FA88; Wed, 23 Dec 2015 11:55:27 +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 70A17A4FA87 for ; Wed, 23 Dec 2015 11:55:27 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: from zxy.spb.ru (zxy.spb.ru [195.70.199.98]) (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 CE52E1CE4 for ; Wed, 23 Dec 2015 11:55:26 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: from slw by zxy.spb.ru with local (Exim 4.86 (FreeBSD)) (envelope-from ) id 1aBi0m-000HuF-Ov; Wed, 23 Dec 2015 14:55:20 +0300 Date: Wed, 23 Dec 2015 14:55:20 +0300 From: Slawa Olhovchenkov To: Stephen Hocking Cc: hackers@freebsd.org Subject: Re: The minimum amount of memory needed to use ZFS. Message-ID: <20151223115520.GB4535@zxy.spb.ru> References: <20151223113216.GA4535@zxy.spb.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: slw@zxy.spb.ru X-SA-Exim-Scanned: No (on zxy.spb.ru); SAEximRunCond expanded to false 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 11:55:27 -0000 On Wed, Dec 23, 2015 at 10:41:13PM +1100, Stephen Hocking wrote: > In my case, I want to use ZFS. I'm currently running FreeBSD on a number of > systems, ranging from 16G (box with multiple ZFS pools and filesystems) to > 256M (Early RPI), so I know it runs OK in relatively small amounts of > memory (aeons ago I was running it one a box with 8MB). I was curious to > know what people think it needs to run ZFS without problems. This depends on average ZFS block size on pool, number of files in working set, number of simultaneously open files, pattern of access to files and etc. Using large block size (1M and more) can significantly reduce memory consumption for ZFS overhead, but you can't cache independence files as much as for 128K. Common rule: if UFS working good in you memory and memory > 512M -- ZFS also will be working good. > On Wed, Dec 23, 2015 at 10:32 PM, Slawa Olhovchenkov wrote: > > > On Wed, Dec 23, 2015 at 09:43:37PM +1100, Stephen Hocking wrote: > > > > > Hi all, > > > > > > Inspired by this article: > > > > > http://arstechnica.com/information-technology/2015/12/rsync-net-zfs-replication-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? > > > > I am do install FreeBSD i386 10 on the VirtualBox VM with 384M RAM and > > successful pass `make buildworld`. > > > > In the real world all depends on workload and minimal depends from FS > > (UFS or ZFS). > >