From owner-freebsd-current@FreeBSD.ORG Thu May 27 08:50:20 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4F77216A4CE for ; Thu, 27 May 2004 08:50:20 -0700 (PDT) Received: from pinus.cc.fer.hr (pinus.cc.fer.hr [161.53.73.18]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9B97743D41 for ; Thu, 27 May 2004 08:50:19 -0700 (PDT) (envelope-from ivoras@fer.hr) Received: from fer.hr (lara.cc.fer.hr [161.53.72.113]) by pinus.cc.fer.hr (8.12.2/8.12.2) with ESMTP id i4RFr8sM017645 for ; Thu, 27 May 2004 17:53:09 +0200 (MEST) Message-ID: <40B60D2E.3050003@fer.hr> Date: Thu, 27 May 2004 17:45:50 +0200 From: Ivan Voras User-Agent: Mozilla Thunderbird 0.5 (Windows/20040207) X-Accept-Language: en-us, en MIME-Version: 1.0 To: current@freebsd.org References: <40B4ECC8.50808@fer.hr> <20040526202849.GA37162@freebie.xs4all.nl> <40B519DA.7000708@fer.hr> <20040527120819.B8434@gamplex.bde.org> <40B5DE26.4040901@fer.hr> <20040527124512.GV63479@cicely12.cicely.de> <40B5E66F.7000507@fer.hr> <20040527140744.GW63479@cicely12.cicely.de> In-Reply-To: <20040527140744.GW63479@cicely12.cicely.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: Softupdates a mount option? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 May 2004 15:50:20 -0000 Bernd Walter wrote: >>>SU makes perfectly sense for swap backed md drives. >> >>I always thought the "swap backed" meant the memory is allocated from the >>same pool as for userland applications, e.g. they only get swapped out if >>memory is scarce. Is this wrong? > > > You are right, but md(4) doesn't know about the filesystem and therefor > can't know which blocks have content to keep and which are unused. > SU now allows files that are deleted quite fast to never touch the > block device and md never need to write those blocks into swap storage > as they never got dirty. As opposed to the 'async' mode? -- Every sufficiently advanced magic is indistinguishable from technology - Arthur C Anticlarke