From owner-freebsd-current@FreeBSD.ORG Wed Aug 3 11:16:30 2005 Return-Path: X-Original-To: freebsd-current@freebsd.org 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 4878E16A41F for ; Wed, 3 Aug 2005 11:16:30 +0000 (GMT) (envelope-from PeterJeremy@optushome.com.au) Received: from mail26.syd.optusnet.com.au (mail26.syd.optusnet.com.au [211.29.133.167]) by mx1.FreeBSD.org (Postfix) with ESMTP id 836D443D48 for ; Wed, 3 Aug 2005 11:16:29 +0000 (GMT) (envelope-from PeterJeremy@optushome.com.au) Received: from cirb503493.alcatel.com.au (c220-239-19-236.belrs4.nsw.optusnet.com.au [220.239.19.236]) by mail26.syd.optusnet.com.au (8.12.11/8.12.11) with ESMTP id j73BGPaw001512 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Wed, 3 Aug 2005 21:16:27 +1000 Received: from cirb503493.alcatel.com.au (localhost.alcatel.com.au [127.0.0.1]) by cirb503493.alcatel.com.au (8.12.10/8.12.10) with ESMTP id j73BGPSR000567; Wed, 3 Aug 2005 21:16:25 +1000 (EST) (envelope-from pjeremy@cirb503493.alcatel.com.au) Received: (from pjeremy@localhost) by cirb503493.alcatel.com.au (8.12.10/8.12.9/Submit) id j73BGO0h000566; Wed, 3 Aug 2005 21:16:24 +1000 (EST) (envelope-from pjeremy) Date: Wed, 3 Aug 2005 21:16:24 +1000 From: Peter Jeremy To: Jeremie Le Hen Message-ID: <20050803111624.GA271@cirb503493.alcatel.com.au> References: <20050802152009.GA29643@mercury.m202.net> <008c01c59777$42db5520$0b02a8c0@justin> <790a9fff050802084439209f7e@mail.gmail.com> <20050802160045.GA61854@freebie.xs4all.nl> <20050803024341.GA92499@over-yonder.net> <20050803082939.GE45385@obiwan.tataz.chchile.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050803082939.GE45385@obiwan.tataz.chchile.org> User-Agent: Mutt/1.4.2i Cc: freebsd-current@freebsd.org Subject: Re: Hot-swap SATA and atacontrol X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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: Wed, 03 Aug 2005 11:16:30 -0000 On Wed, 2005-Aug-03 10:29:39 +0200, Jeremie Le Hen wrote: >More seriously, I don't see the point in using sync(8) three times >consecutively, except that's an indirect method to wait for the disk >buffers to be flushed before powering down. Please, correct me if I'm >wrong. The response I've seen on the PUPS or TUHS mailing list when this was asked is (roughly): The time taken to type sync three times on a KSR33 is a good match for the time it takes a PDP-11 to flush its buffers to a RK05. There is absolutely no point in typing sync before unmounting filesystems or halting any modern Unix - they all flush their buffers as part of the unmount or halt processing. (And the invention of of FS_UNCLEAN means that mount and fsck know whether the filesystem was unmounted cleanly or not). -- Peter Jeremy