From owner-freebsd-hackers@FreeBSD.ORG Mon Sep 29 17:29:51 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C384F16A4B3 for ; Mon, 29 Sep 2003 17:29:51 -0700 (PDT) Received: from pop016.verizon.net (pop016pub.verizon.net [206.46.170.173]) by mx1.FreeBSD.org (Postfix) with ESMTP id C6E234401E for ; Mon, 29 Sep 2003 17:29:49 -0700 (PDT) (envelope-from babkin@bellatlantic.net) Received: from bellatlantic.net ([138.89.157.47]) by pop016.verizon.net (InterMail vM.5.01.05.33 201-253-122-126-133-20030313) with ESMTP id <20030930002947.HSGO10125.pop016.verizon.net@bellatlantic.net>; Mon, 29 Sep 2003 19:29:47 -0500 Sender: root@FreeBSD.ORG Message-ID: <3F78CE77.5878B57A@bellatlantic.net> Date: Mon, 29 Sep 2003 20:29:43 -0400 From: Sergey Babkin X-Mailer: Mozilla 4.7 [en] (X11; U; FreeBSD 4.7-RELEASE i386) X-Accept-Language: en, ru MIME-Version: 1.0 To: Peter Jeremy References: <3F775D41.DF780001@bellatlantic.net> <20030929075809.GA3062@server.c211-28-27-130.belrs2.nsw.optusnet.com.au> Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: 7bit X-Authentication-Info: Submitted using SMTP AUTH at pop016.verizon.net from [138.89.157.47] at Mon, 29 Sep 2003 19:29:46 -0500 cc: hackers@freebsd.org Subject: Re: has anyone installed 5.1 from a SCSI CD? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Sep 2003 00:29:51 -0000 Peter Jeremy wrote: > > On Sun, Sep 28, 2003 at 06:14:25PM -0400, Sergey Babkin wrote: > >BTW, I have another related issue too: since at least 4.7 > >all the disk device nodes have charcater device entries in /dev. > > As of December 1999 - which is before 4.0-RELEASE. This was well > advertised and discussed at the time. Your objections are about > 4 years too late. Well, the previous version I installed was 4.0-snapshot that did not have this change yet. Also it's never too late to fix the broken things. > >That's very, very wrong. Even though there may be no difference > >any more between the charcater and block drivers, the type of > >device node still conveys the information about device types > >to the applications. One case in point being a viewer application > >(if anyone is interested, http://nac.sf.net ) which must handle > >the sequential and random-access devices differently: > > 'block' vs 'character' has nothing to do with random or sequential > access and any application that thinks it does is broken. Any > application that directly accesses devices must understand all the > various quirks - ability to seek, block size(s) supported, side- The random-access devices are seekable by definition. And the OS interface is there to hide the block size issues. > The only purpose for block devices was to provide a cache for disk > devices. It makes far more sense for this caching to be tightly > coupled into the filesystem code where the cache characteristics > can be better controlled. What I'm saying is that it's good to have an easy way for applications to distinguish the random-access devices from the sequential-only-acces devices. Are they cacned internally or not is not that much of an application's concern. -SB