Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751010AbWKCL4i (ORCPT ); Fri, 3 Nov 2006 06:56:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751151AbWKCL4i (ORCPT ); Fri, 3 Nov 2006 06:56:38 -0500 Received: from artax.karlin.mff.cuni.cz ([195.113.31.125]:41680 "EHLO artax.karlin.mff.cuni.cz") by vger.kernel.org with ESMTP id S1751010AbWKCL4h (ORCPT ); Fri, 3 Nov 2006 06:56:37 -0500 Date: Fri, 3 Nov 2006 12:56:36 +0100 (CET) From: Mikulas Patocka To: =?iso-8859-1?Q?J=F6rn?= Engel Cc: linux-kernel@vger.kernel.org Subject: Re: New filesystem for Linux In-Reply-To: <20061103101901.GA11947@wohnheim.fh-wedel.de> Message-ID: References: <20061102235920.GA886@wohnheim.fh-wedel.de> <20061103101901.GA11947@wohnheim.fh-wedel.de> X-Personality-Disorder: Schizoid MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="1908636959-327896193-1162554996=:17174" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1431 Lines: 34 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --1908636959-327896193-1162554996=:17174 Content-Type: TEXT/PLAIN; charset=iso-8859-2; format=flowed Content-Transfer-Encoding: 8BIT >>>> new method to keep data consistent in case of crashes (instead of >>>> journaling), >>> >>> Your 32-bit transaction counter will overflow in the real world. It >>> will take a setup with millions of transactions per second and even >>> then not trigger for a few years, but when it hits your filesystem, >>> the administrator of such a beast won't be happy at all. :) >> >> If it overflows, it increases crash count instead. So really you have 2^47 >> transactions or 65536 crashes and 2^31 transactions between each crash. > > I am fully aware the counters are effectively 48-bit. If they were > just 32-bit, you would likely have hit the problem yourself already. > > J?rn Given the seek time 0.01s, 31-bit value would last for minimum time of 248 days when doing only syncs and nothing else. 47-bit value will last for reasonably long. Mikulas --1908636959-327896193-1162554996=:17174-- - 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/