From owner-freebsd-questions@FreeBSD.ORG Thu Feb 7 07:36:28 2008 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 0F90716A420 for ; Thu, 7 Feb 2008 07:36:28 +0000 (UTC) (envelope-from wundram@beenic.net) Received: from mail.beenic.net (mail.beenic.net [83.246.72.40]) by mx1.freebsd.org (Postfix) with ESMTP id B53C213C51B for ; Thu, 7 Feb 2008 07:36:27 +0000 (UTC) (envelope-from wundram@beenic.net) Received: from [192.168.1.32] (a89-182-28-93.net-htp.de [89.182.28.93]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.beenic.net (Postfix) with ESMTP id 9B9F7A44529 for ; Thu, 7 Feb 2008 08:36:26 +0100 (CET) From: "Heiko Wundram (Beenic)" Organization: Beenic Networks GmbH To: freebsd-questions@freebsd.org Date: Thu, 7 Feb 2008 08:37:54 +0100 User-Agent: KMail/1.9.7 References: <50460.33951.qm@web34512.mail.mud.yahoo.com> <200802070818.45400.wundram@beenic.net> <47AAB28F.10705@bsdforen.de> In-Reply-To: <47AAB28F.10705@bsdforen.de> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200802070837.54337.wundram@beenic.net> Subject: Re: Some ideas for FreeBSD 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: Thu, 07 Feb 2008 07:36:28 -0000 Am Donnerstag, 7. Februar 2008 08:26:07 schrieb Dominic Fandrey: > Heiko Wundram (Beenic) wrote: > > Am Donnerstag, 7. Februar 2008 07:32:16 schrieb Jason C. Wells: > >> Norberto Meijome wrote: > >>> But I agree with Wojciech..do you really want to use swap files? > >> > >> One could mount an md filesystem and then use that as swap. That way > >> you wouldn't need to use any disc space. As a plus, the performance > >> would be way better than disc. > > > > Ahem, sorry, that's just plain stupid. Either the md system is backed up > > by RAM (in which case you don't need the swap anyway; why'd you want to > > access RAM by putting it in a swap on an md in RAM?), or it's backed up > > by swap, in which case you have a chicken and egg problem. > > Or it's backed by a file (-t vnode, which is implicated by -f). I have used > files for swap, just to see weather it works, others have done it because > they had to. True, sorry I forgot to mention that, but swapping to a file (based on a standard disk) won't get you any speed-ups relative to a (dedicated) swap-partition on a disk either, and that's (if I understood the original poster properly) what was suggested. I can understand the need for swap files (esp. in some environments where there's no easy way to just add physical memory or disk space for a task requiring huge amounts of it), but generally they offer no speed up at all to a dedicated swap (or memory in itself). -- Heiko Wundram Product & Application Development