From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Mon, 07 Apr 2008 14:58:39 -0700 (PDT) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with SMTP id m37LwSvl002118 for ; Mon, 7 Apr 2008 14:58:31 -0700 Date: Tue, 8 Apr 2008 07:58:55 +1000 From: David Chinner Subject: Re: Does XFS prevent disk spindown? Message-ID: <20080407215855.GE108924158@sgi.com> References: <20080401003005.GJ103491721@sgi.com> <47F1CF6D.2040103@sandeen.net> <47F9735E.8020900@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Thor Kristoffersen Cc: Timothy Shimmin , xfs@oss.sgi.com On Mon, Apr 07, 2008 at 10:33:19PM +0200, Thor Kristoffersen wrote: > Timothy Shimmin writes: > > Thor Kristoffersen wrote: > >>> Use blktrace, or echo 1 > /proc/sys/vm/block_dump to see what block and > >>> who's writing it... it's probably the superblock? what kernel? > >> > >> This is kernel version 2.6.24. More specifically it's a Debian kernel from > >> package linux-image-2.6.24-1-686 (2.6.24-4). > >> > >> I put the system in runlevel 1 and executed the test as you suggested. On > >> /dev/sda3 I have mounted (with noatime) an XFS filesystem that contains > >> data that is not supposed to be accessed by any process. In the output > >> below I have filtered out all accesses to other partitions. (BTW, this is > >> not actually the disk that I wanted to spin down, but I think the log > >> proves my point.) > >> > >> > > I'm wondering if that is writing to the xfs ondisk log/journal in those cases. > > What does 'xfs_logprint -t' show in these "idle" states > > after these writes? > > xfs_logprint produces output like the one shown below, so it does indeed > look like it's writing to the journal. But why should it need to keep > writing to the journal when there have been no updates to any files on that > partition recently? Are you using lazy-count=1? (i.e. output of 'xfs_info ', please). Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group