From owner-freebsd-stable@FreeBSD.ORG Tue Apr 19 21:02:11 2005 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 49F3516A4CE for ; Tue, 19 Apr 2005 21:02:11 +0000 (GMT) Received: from smtp.owt.com (smtp.owt.com [204.118.6.19]) by mx1.FreeBSD.org (Postfix) with ESMTP id E4B3843D48 for ; Tue, 19 Apr 2005 21:02:10 +0000 (GMT) (envelope-from kstewart@owt.com) Received: from [207.41.94.233] (owt-207-41-94-233.owt.com [207.41.94.233]) by smtp.owt.com (8.12.8/8.12.8) with ESMTP id j3JL1DUF031085; Tue, 19 Apr 2005 14:01:14 -0700 From: Kent Stewart To: freebsd-stable@freebsd.org Date: Tue, 19 Apr 2005 14:02:04 -0700 User-Agent: KMail/1.8 References: <426447F8.5090209@charter.net> <20050419163237.76a99373.wmoran@potentialtech.com> <20050419203913.GB50313@dan.emsphone.com> In-Reply-To: <20050419203913.GB50313@dan.emsphone.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200504191402.04374.kstewart@owt.com> cc: Dan Nelson cc: Bill Moran Subject: Re: Newbie Question About System Update X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Apr 2005 21:02:11 -0000 On Tuesday 19 April 2005 01:39 pm, Dan Nelson wrote: > In the last episode (Apr 19), Bill Moran said: > > Chuck Swiger wrote: > > > Bill Moran wrote: > > > > The system can not replace programs that are in use, > > > > > > This is generally not the case. Unix lets you continue to access > > > a file after it has been deleted, so long as the process hangs on > > > to a file descriptor. This lets you replace programs in use, > > > without running into the same problems that platforms like > > > Windows have. > > > > What you say?: > > > > bash-2.05b$ su > > Password: > > bolivia# cp /usr/sbin/cron /home/wmoran/. > > bolivia# cp /home/wmoran/cron /usr/sbin/. > > cp: /usr/sbin/./cron: Text file busy > > bolivia# > > > > Notice that /usr/sbin/cron is in use (because my system is running > > normally) I can copy _from_ that file, but I can not overwrite it. > > What you can do, however, is: create the new file under a temporary > name, delete the original, and rename the temp file to the orignal's > name, which is what /usr/bin/install does. I've done many > installworlds on running systems without problems. You are forgetting that one of the real purposes of the boot -s is to test your new kernel. If you have never been bitten by a kernel that would only panic, you have no problems. If you have, you know that you can boot the old kernel and continue without any problems until some one solves the panic. You will not most likely hit that situation on a security based version but this is freebsd-stable and it can happen at any time. My attitude is that if you don't boot -s, you are simply playing Russian-roulette with your system. Some day, it will bite you. Kent -- Kent Stewart Richland, WA http://users.owt.com/kstewart/index.html