From owner-freebsd-arm@FreeBSD.ORG Wed Jul 2 02:20:47 2014 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 2CCF2ED; Wed, 2 Jul 2014 02:20:47 +0000 (UTC) Received: from h2.funkthat.com (gate2.funkthat.com [208.87.223.18]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "funkthat.com", Issuer "funkthat.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id DEB7B296B; Wed, 2 Jul 2014 02:20:46 +0000 (UTC) Received: from h2.funkthat.com (localhost [127.0.0.1]) by h2.funkthat.com (8.14.3/8.14.3) with ESMTP id s622KglY060851 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 1 Jul 2014 19:20:43 -0700 (PDT) (envelope-from jmg@h2.funkthat.com) Received: (from jmg@localhost) by h2.funkthat.com (8.14.3/8.14.3/Submit) id s622KggZ060850; Tue, 1 Jul 2014 19:20:42 -0700 (PDT) (envelope-from jmg) Date: Tue, 1 Jul 2014 19:20:42 -0700 From: John-Mark Gurney To: Anton Shterenlikht Subject: Re: /tmp, /var/log, /var/tmp as /dev/md - why? Message-ID: <20140702022042.GG45513@funkthat.com> Mail-Followup-To: Anton Shterenlikht , rene@freebsd.org, freebsd-arm@freebsd.org References: <201407011046.s61AkJpj006890@mech-cluster241.men.bris.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201407011046.s61AkJpj006890@mech-cluster241.men.bris.ac.uk> User-Agent: Mutt/1.4.2.3i X-Operating-System: FreeBSD 7.2-RELEASE i386 X-PGP-Fingerprint: 54BA 873B 6515 3F10 9E88 9322 9CB1 8F74 6D3F A396 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html X-TipJar: bitcoin:13Qmb6AeTgQecazTWph4XasEsP7nGRbAPE X-to-the-FBI-CIA-and-NSA: HI! HOW YA DOIN? can i haz chizburger? X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.2 (h2.funkthat.com [127.0.0.1]); Tue, 01 Jul 2014 19:20:43 -0700 (PDT) Cc: freebsd-arm@freebsd.org X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Jul 2014 02:20:47 -0000 Anton Shterenlikht wrote this message on Tue, Jul 01, 2014 at 11:46 +0100: > >From r.c.ladan@gmail.com Tue Jul 1 11:37:35 2014 > > > >2014-07-01 11:25 GMT+02:00 Anton Shterenlikht : > > > >> Why is it a good idea to mount /tmp and some var dirs on memory disks: > >> > >> root@raspberry-pi:/usr/ports # df -m > >> Filesystem 1M-blocks Used Avail Capacity Mounted on > >> /dev/mmcsd0s2a 14694 777 12742 6% / > >> devfs 0 0 0 100% /dev > >> /dev/mmcsd0s1 16 3 13 20% /boot/msdos > >> /dev/md0 28 4 22 16% /tmp > >> /dev/md1 14 0 12 0% /var/log > >> /dev/md2 4 0 4 0% /var/tmp > >> root@raspberry-pi:/usr/ports # > >> > >> Is this about speed or power, or maybe space? > >> > >> Mostly write tear because you're using an SD card, and it improves speed > >too. > > "write tear"? > Is this a joke, or some technical term? > I cannot find what it means. it is a technical term, though I'd be surprised if any SD card had an issue w/ that anymore... write tear is where when writing data, only part of the data gets written and then you loose power... This is mostly an issue on flash where you have to erase the data beforey ou can program it... Most flash now have a layer of indirection so that they copy/write the data to a new flash block, and then point the block there before erasing the old data... (kinda like a log FS)... > I get these messages on the console (well, on hdmi port...): > > pid ... (svnlite), uid 0 inumber 13 on /tmp: filesystem full > > If I unmount /tmp from md and leave it on sd card, > then I don't see these anymore. What does this mean? I means that your /tmp fs is to small, and you should either increase the size of it, or clean it out... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."