From owner-freebsd-questions@FreeBSD.ORG Sat Feb 18 14:54:40 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 115451065672 for ; Sat, 18 Feb 2012 14:54:40 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: from mail-wi0-f182.google.com (mail-wi0-f182.google.com [209.85.212.182]) by mx1.freebsd.org (Postfix) with ESMTP id 8C1998FC0C for ; Sat, 18 Feb 2012 14:54:39 +0000 (UTC) Received: by mail-wi0-f182.google.com with SMTP id hn14so3284684wib.13 for ; Sat, 18 Feb 2012 06:54:39 -0800 (PST) Received-SPF: pass (google.com: domain of rwmaillists@googlemail.com designates 10.180.86.198 as permitted sender) client-ip=10.180.86.198; Authentication-Results: mr.google.com; spf=pass (google.com: domain of rwmaillists@googlemail.com designates 10.180.86.198 as permitted sender) smtp.mail=rwmaillists@googlemail.com; dkim=pass header.i=rwmaillists@googlemail.com Received: from mr.google.com ([10.180.86.198]) by 10.180.86.198 with SMTP id r6mr5448323wiz.22.1329576879330 (num_hops = 1); Sat, 18 Feb 2012 06:54:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=date:from:to:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type:content-transfer-encoding; bh=ULDyPugjsWAkr5eh6SsBgM9UC11QNiOmldpXe5UKYLA=; b=e6NeSUJOGiT2Gr+Lfi6jbkG2mKrNBrJxK0snpIdE8mpcWw/SiGDbnl2imS7MZ9SuIK JzBiCvpuQEf62cQDi4JohLoBUERiK8d0KktijkS/QWHcAAuOUXxfBhAdYbvHbeeu/Rhd vDUDsfacHsy8+kMxuvjpY1q/8lR7cwf+Pyixg= Received: by 10.180.86.198 with SMTP id r6mr4621702wiz.22.1329576879294; Sat, 18 Feb 2012 06:54:39 -0800 (PST) Received: from gumby.homeunix.com (87-194-105-247.bethere.co.uk. [87.194.105.247]) by mx.google.com with ESMTPS id n5sm10037375wiw.7.2012.02.18.06.54.37 (version=SSLv3 cipher=OTHER); Sat, 18 Feb 2012 06:54:38 -0800 (PST) Date: Sat, 18 Feb 2012 14:54:35 +0000 From: RW To: freebsd-questions@freebsd.org Message-ID: <20120218145435.5f7efb37@gumby.homeunix.com> In-Reply-To: <4F3EEC58.1000308@fisglobal.com> References: <4F3ECF23.5000706@fisglobal.com> <20120217234623.cf7e169c.freebsd@edvax.de> <20120217225329.GB30014@gizmo.acns.msu.edu> <021101ccedc9$89445cf0$9bcd16d0$@fisglobal.com> <290E977C-E361-4C7D-8F1E-C1D6D03BAD63@mac.com> <4F3EEC58.1000308@fisglobal.com> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.6; amd64-portbld-freebsd8.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: One or Four? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 18 Feb 2012 14:54:40 -0000 On Fri, 17 Feb 2012 16:10:00 -0800 Robison, Dave wrote: > On 02/17/2012 15:55, Chuck Swiger wrote: > > > > Yes. It works as intended even when /tmp is part of a single root > > partition; although mounting /tmp as a RAM- or swap-based tmpfs > > filesystem might be better for many situations. > > Sure it has its uses, but now you're jumping into new territory where > the installer has to either ask the user to create tmpfs or make the > decision to do it on its own. As has been stated, this is fine if > sufficient RAM is available. Personally I don't like using RAM for > tmp. The only option for a genuinely ram-backed /tmp is something that you should probably never use for anything, a malloc-backed md device using wired kernel memory. If there is a good reason for that I can't think of it, it keeps all files, even deleted ones, in memory even at the expense of the processes that are accessing the files. The practical choices are tmpfs or (if you don't trust tmpfs) a swap-backed md device. Both of these use swap-backed storage via the normal VM/Caching-system. tmpfs files tend to stay cached longer than on a normal UFS partition (because there's no deadline for writing out dirty pages) but that's generally what you want. In my experience /tmpfs works well whether you have too little or too much memory. I've been using it for building ports for a long time, and it works fine even on ports that couldn't be built on ufs without swap usage.