From owner-freebsd-hackers@FreeBSD.ORG Wed May 4 21:16:23 2005 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 0E76A16A4CE for ; Wed, 4 May 2005 21:16:23 +0000 (GMT) Received: from smtp813.mail.ukl.yahoo.com (smtp813.mail.ukl.yahoo.com [217.12.12.203]) by mx1.FreeBSD.org (Postfix) with SMTP id 3E48043D70 for ; Wed, 4 May 2005 21:16:22 +0000 (GMT) (envelope-from Thomas.Sparrevohn@btinternet.com) Received: from unknown (HELO w2fzz0vc01.aah-go-on.com) (thomas.sparrevohn@hg1.btinternet.com@81.157.225.3 with plain) by smtp813.mail.ukl.yahoo.com with SMTP; 4 May 2005 21:15:30 -0000 From: Thomas Sparrevohn To: freebsd-hackers@freebsd.org Date: Wed, 4 May 2005 22:15:25 +0100 User-Agent: KMail/1.8 References: <20050503120958.Y42342@eleanor.us1.wmi.uvac.net> <20050503222512.GA53874@crow.addict.de> <20050503.233855.116351361.imp@bsdimp.com> In-Reply-To: <20050503.233855.116351361.imp@bsdimp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200505042215.26426.Thomas.Sparrevohn@btinternet.com> Subject: Re: mergemaster improvement (auto-update for not modified files) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: Thomas.Sparrevohn@btinternet.com List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 May 2005 21:16:23 -0000 On Wednesday 04 May 2005 06:38, M. Warner Losh wrote: > > The technical reasons are very simple. If a new system call is > created, and programs use that new system call, then if you do an > installworld before you boot the kernel, that can result in binaries > not working. This has happened with important ones like /bin/sh in > the past. In addition, if you aren't running single user, many > different races exist in the installation process that can result in > bad behavior. There are also potential problems with symbols in > there's a large jump between the revisions being updated. > > Usually you can get away with it, but if you want to be safe, you must > do the install in single user. Usually, however, has lead in the past > to problems, which is why the project recommendations are > conservative. > A auto-scripted install directly run from rc.d in single-user mode would cover both requirements - I seem to recall that Solaris had something like it at a point. Somewhat along the lines of nextboot would be nice.