From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Thu, 29 May 2008 01:08:48 -0700 (PDT) Received: from cuda.sgi.com ([192.48.176.15]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m4T88kuh014091 for ; Thu, 29 May 2008 01:08:46 -0700 Received: from mail.lichtvoll.de (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 8AEE01B986AF for ; Thu, 29 May 2008 01:09:38 -0700 (PDT) Received: from mail.lichtvoll.de (mondschein.lichtvoll.de [194.150.191.11]) by cuda.sgi.com with ESMTP id y1RNn1yzFqXyRwBU for ; Thu, 29 May 2008 01:09:38 -0700 (PDT) Received: from [10.0.0.21] (e179054170.adsl.alicedsl.de [85.179.54.170]) by mail.lichtvoll.de (Postfix) with ESMTP id D1B9B5ADEF for ; Thu, 29 May 2008 10:09:55 +0200 (CEST) From: Martin Steigerwald Subject: Re: Question for XFS (mounting and clean bit) Date: Thu, 29 May 2008 10:09:35 +0200 References: <20080527181336.22qjfcgcfdlwsg40@webmail.versatel.de> <483E5462.1080604@sgi.com> (sfid-20080529_093513_291114_64DAE2F5) In-Reply-To: <483E5462.1080604@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200805291009.36229.Martin@lichtvoll.de> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: linux-xfs@oss.sgi.com Am Donnerstag 29 Mai 2008 schrieb Timothy Shimmin: > Hi Andre, Hi Timothy, > I didn't follow all of this, sorry. > When you ask about the "clean bit", I assume that you are referring > to "clean XFS mount for filesystem". > We effectively mark it clean if we do a successful unmount. > As part of unmount, we write an unmount record into the xfs log. > On the next mount we look for the head of the log and then for the > unmount record nearby. If we find the unmount record then we know > we have had a clean unmount previously, otherwise we replay the log. > So it's really a question of doing an unmount versus resetting the > box beforehand or forcing a shutdown beforehand. But when is it dirtied? If the clean log entry is the actual "clean bit" I guess: When the first new entry is written in the log. Does XFS write a log entry on mounting it already or only on the first real write? Or in other words if I mount a XFS filesystem without writing to it and reset the machine, would it be marked clean or dirty then? Hmmm, I could test this ;-). If its only mounted read only, it shouldn't be marked dirty anyways. Ciao, -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7