Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759340AbZDAPlq (ORCPT ); Wed, 1 Apr 2009 11:41:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752316AbZDAPlh (ORCPT ); Wed, 1 Apr 2009 11:41:37 -0400 Received: from mo-p05-ob.rzone.de ([81.169.146.182]:55471 "EHLO mo-p05-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751730AbZDAPlg (ORCPT ); Wed, 1 Apr 2009 11:41:36 -0400 X-RZG-AUTH: :LWIQcGC8af5qXkYNYt77sURZEFmV4M3TAgvB+Qeh4tE+44JfzNbYY5/NAUgO X-RZG-CLASS-ID: mo05 Message-ID: <49D38B22.1050105@ursus.ath.cx> Date: Wed, 01 Apr 2009 17:41:22 +0200 From: "Andreas T.Auer" User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: Chris Mason CC: Dave Chinner , Mark Lord , Stefan Richter , Jeff Garzik , Linus Torvalds , Matthew Garrett , Alan Cox , Theodore Tso , Andrew Morton , David Rees , Jesper Krogh , Linux Kernel Mailing List Subject: Re: Linux 2.6.29 References: <49CD7B10.7010601@garzik.org> <49CD891A.7030103@rtr.ca> <49CD9047.4060500@garzik.org> <49CE2633.2000903@s5r6.in-berlin.de> <49CE3186.8090903@garzik.org> <49CE35AE.1080702@s5r6.in-berlin.de> <49CE3F74.6090103@rtr.ca> <20090329231451.GR26138@disturbed> <1238417751.30488.12.camel@think.oraclecorp.com> <20090331235509.GU26138@disturbed> <1238590413.18549.7.camel@think.oraclecorp.com> In-Reply-To: <1238590413.18549.7.camel@think.oraclecorp.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1581 Lines: 41 On 01.04.2009 14:53 Chris Mason wrote: > On Wed, 2009-04-01 at 10:55 +1100, Dave Chinner wrote: > >> If you crash while rsync is running, then the state of the copy >> is garbage anyway. You have to restart from scratch and rsync will >> detect such failures and resync the file. gnome/kde have no >> mechanism for such recovery. >> > If this were the recovery system they had in mind, then why use rename > at all? They could just as easily overwrite the original in place. > It is not a recovery system. The renaming procedure is almost atomic with e.g. reiser or ext3 (ordered), but simple overwriting would always leave a window between truncating and the complete rewrite of the file. > Using rename implies they want to replace the old with a complete new > version. > > There's also the window where you crash after the rsync is done but > before all the new data safely makes it into the replacement files. > Sure, but in that case you have only lost some of your _mirrored_ data. The original will usually be untouched by this. So after the restart you just start the mirroring process again, and hopefully, this time you get a perfect copy. In KDE and lots of other apps the _original_ config files (and not any copies) are "overlinked" with the new files by the rename. That's the difference. Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/