From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Sat, 05 Apr 2008 07:02:27 -0700 (PDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.168.29]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m35E19L1028110 for ; Sat, 5 Apr 2008 07:01:10 -0700 Received: from smtp.getmail.no (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 7C102749DDF for ; Sat, 5 Apr 2008 07:01:44 -0700 (PDT) Received: from smtp.getmail.no (smtp.getmail.no [84.208.20.33]) by cuda.sgi.com with ESMTP id DouqbHRA4Rs1kEca for ; Sat, 05 Apr 2008 07:01:44 -0700 (PDT) Received: from pmxchannel-daemon.no-osl-m323-srv-009-z2.isp.get.no by no-osl-m323-srv-009-z2.isp.get.no (Sun Java System Messaging Server 6.2-7.05 (built Sep 5 2006)) id <0JYU00C0DUYUMT00@no-osl-m323-srv-009-z2.isp.get.no> for xfs@oss.sgi.com; Sat, 05 Apr 2008 16:01:42 +0200 (CEST) Received: from smtp.getmail.no ([10.5.16.1]) by no-osl-m323-srv-009-z2.isp.get.no (Sun Java System Messaging Server 6.2-7.05 (built Sep 5 2006)) with ESMTP id <0JYU007PPUYGDX40@no-osl-m323-srv-009-z2.isp.get.no> for xfs@oss.sgi.com; Sat, 05 Apr 2008 16:01:28 +0200 (CEST) Received: from localhost ([84.215.109.218]) by no-osl-m323-srv-004-z1.isp.get.no (Sun Java System Messaging Server 6.2-7.05 (built Sep 5 2006)) with ESMTP id <0JYU0011GUYGU880@no-osl-m323-srv-004-z1.isp.get.no> for xfs@oss.sgi.com; Sat, 05 Apr 2008 16:01:28 +0200 (CEST) Received: from thor by localhost with local (Exim 4.69 #1 (Debian)) id 1Ji8xU-0000Jh-5o for ; Sat, 05 Apr 2008 16:01:28 +0200 Date: Sat, 05 Apr 2008 16:01:28 +0200 From: Thor Kristoffersen Subject: Re: Does XFS prevent disk spindown? In-reply-to: Message-id: MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT References: <20080401003005.GJ103491721@sgi.com> <47F1CF6D.2040103@sandeen.net> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: xfs@oss.sgi.com (It looks like my reply never made it to the list so I'm trying again.) Eric Sandeen writes: > David Chinner wrote: >> On Mon, Mar 31, 2008 at 08:26:00PM +0200, Thor Kristoffersen wrote: >>> I've noticed that when I spin down XFS-mounted disks they spin up again >>> shortly afterwards. I used iostat to monitor disk accesses to a mounted >>> partition (with noatime) in single user mode. Apparently there is a write >>> access to the partition approximately every 35 seconds, even if the >>> partition is idle. As far as I can understand, since there is no data that >>> needs to be flushed this must be done by an XFS daemon for some purpose. > > 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.) Thor ------------------------------------------------------ Tue Apr 1 18:51:27 CEST 2008 xfssyncd(3426): WRITE block 682946473 on sda3 Tue Apr 1 18:51:32 CEST 2008 Tue Apr 1 18:51:37 CEST 2008 Tue Apr 1 18:51:42 CEST 2008 Tue Apr 1 18:51:47 CEST 2008 Tue Apr 1 18:51:52 CEST 2008 Tue Apr 1 18:51:57 CEST 2008 Tue Apr 1 18:52:02 CEST 2008 xfssyncd(3426): WRITE block 682946475 on sda3 Tue Apr 1 18:52:07 CEST 2008 Tue Apr 1 18:52:12 CEST 2008 Tue Apr 1 18:52:17 CEST 2008 Tue Apr 1 18:52:22 CEST 2008 Tue Apr 1 18:52:27 CEST 2008 Tue Apr 1 18:52:32 CEST 2008 Tue Apr 1 18:52:37 CEST 2008 Tue Apr 1 18:52:42 CEST 2008 xfssyncd(3426): WRITE block 682946477 on sda3 Tue Apr 1 18:52:47 CEST 2008 Tue Apr 1 18:52:52 CEST 2008 Tue Apr 1 18:52:57 CEST 2008 Tue Apr 1 18:53:02 CEST 2008 Tue Apr 1 18:53:07 CEST 2008 Tue Apr 1 18:53:12 CEST 2008 Tue Apr 1 18:53:17 CEST 2008 xfssyncd(3426): WRITE block 682946479 on sda3 Tue Apr 1 18:53:22 CEST 2008 Tue Apr 1 18:53:27 CEST 2008 Tue Apr 1 18:53:32 CEST 2008 Tue Apr 1 18:53:37 CEST 2008 Tue Apr 1 18:53:42 CEST 2008 Tue Apr 1 18:53:47 CEST 2008 Tue Apr 1 18:53:52 CEST 2008 xfssyncd(3426): WRITE block 682946481 on sda3 Tue Apr 1 18:53:57 CEST 2008 Tue Apr 1 18:54:02 CEST 2008 Tue Apr 1 18:54:07 CEST 2008 Tue Apr 1 18:54:12 CEST 2008 Tue Apr 1 18:54:17 CEST 2008 Tue Apr 1 18:54:22 CEST 2008 Tue Apr 1 18:54:27 CEST 2008 xfssyncd(3426): WRITE block 682946483 on sda3 Tue Apr 1 18:54:32 CEST 2008 Tue Apr 1 18:54:37 CEST 2008 Tue Apr 1 18:54:42 CEST 2008 Tue Apr 1 18:54:47 CEST 2008 Tue Apr 1 18:54:52 CEST 2008 Tue Apr 1 18:54:57 CEST 2008 Tue Apr 1 18:55:02 CEST 2008 xfssyncd(3426): WRITE block 682946485 on sda3 Tue Apr 1 18:55:07 CEST 2008 Tue Apr 1 18:55:12 CEST 2008 Tue Apr 1 18:55:17 CEST 2008 Tue Apr 1 18:55:22 CEST 2008 Tue Apr 1 18:55:27 CEST 2008 Tue Apr 1 18:55:32 CEST 2008 Tue Apr 1 18:55:37 CEST 2008 xfssyncd(3426): WRITE block 682946487 on sda3 Tue Apr 1 18:55:42 CEST 2008 Tue Apr 1 18:55:47 CEST 2008 Tue Apr 1 18:55:52 CEST 2008 Tue Apr 1 18:55:57 CEST 2008 Tue Apr 1 18:56:02 CEST 2008 Tue Apr 1 18:56:07 CEST 2008 Tue Apr 1 18:56:12 CEST 2008 Tue Apr 1 18:56:17 CEST 2008 xfssyncd(3426): WRITE block 682946489 on sda3 Tue Apr 1 18:56:22 CEST 2008 Tue Apr 1 18:56:27 CEST 2008 Tue Apr 1 18:56:32 CEST 2008 Tue Apr 1 18:56:37 CEST 2008 Tue Apr 1 18:56:42 CEST 2008 Tue Apr 1 18:56:47 CEST 2008 Tue Apr 1 18:56:52 CEST 2008 xfssyncd(3426): WRITE block 682946491 on sda3 Tue Apr 1 18:56:57 CEST 2008 Tue Apr 1 18:57:02 CEST 2008 Tue Apr 1 18:57:07 CEST 2008 Tue Apr 1 18:57:12 CEST 2008 Tue Apr 1 18:57:17 CEST 2008 Tue Apr 1 18:57:22 CEST 2008 Tue Apr 1 18:57:27 CEST 2008 xfssyncd(3426): WRITE block 682946493 on sda3 Tue Apr 1 18:57:32 CEST 2008 Tue Apr 1 18:57:37 CEST 2008 Tue Apr 1 18:57:42 CEST 2008 Tue Apr 1 18:57:47 CEST 2008 Tue Apr 1 18:57:52 CEST 2008 Tue Apr 1 18:57:57 CEST 2008 Tue Apr 1 18:58:02 CEST 2008 xfssyncd(3426): WRITE block 682946495 on sda3 Tue Apr 1 18:58:07 CEST 2008 Tue Apr 1 18:58:12 CEST 2008 Tue Apr 1 18:58:17 CEST 2008 Tue Apr 1 18:58:22 CEST 2008