From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: ext4 lazytime: ctime of some files changed Date: Wed, 13 May 2015 22:17:28 -0400 Message-ID: <20150514021728.GA28473@thunk.org> References: <55531AE3.7030704@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-fsdevel@vger.kernel.org To: =?iso-8859-1?Q?J=F6rg-Volker?= Peetz Return-path: Received: from imap.thunk.org ([74.207.234.97]:35283 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753839AbbENCRb (ORCPT ); Wed, 13 May 2015 22:17:31 -0400 Content-Disposition: inline In-Reply-To: <55531AE3.7030704@web.de> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, May 13, 2015 at 11:35:31AM +0200, J=F6rg-Volker Peetz wrote: >=20 > on my laptop with ext4 fs (on SSD) I started to try the lazytime moun= t option > using a self compiled kernel 4.0.2 on a debian system with mount vers= ion 2.26.2. > Before that, I've used the noatime mount option. >=20 > After restarting the system with an adapted /etc/fstab file and the k= ernel > parameter "rootflags=3Dlazytime", the relatime mount option was also = set. I > changed that by commanding "mount -o remount,strictatime /", etc. The lazytime flag is independent of strictatime/relatime/noatime. And the default is relatime. So when you replaced noatime with lazytime, it's not surprising that you saw the relatime mount option being set. > By accident, I noticed that some files had a modified ctime and mtime= although > they were not changed or modified. >=20 > Has anybody else experienced that? Do I miss a patch? I haven't seen this myself. > Mount options in fstab: nobarrier,lazytime,errors=3Dremount-ro > The filesystems are ext4 on a primary partition of the SSD with defau= lt mount > option journal_data_writeback. I created them in Feb 2011. >=20 > By the way, the command "mount -o remount,lazytime /" does not do the= switch to > lazytime. # grep sda3 /proc/mounts /dev/sda3 / ext4 rw,relatime,errors=3Dremount-ro,data=3Dordered 0 0 # mount -o remount,lazytime / # grep sda3 /proc/mounts /dev/sda3 / ext4 rw,lazytime,relatime,errors=3Dremount-ro,data=3Dordere= d 0 0 # uname -a Linux closure 4.1.0-rc2-11633-gef8a5d0 #125 SMP Tue May 5 21:21:08 EDT = 2015 x86_64 GNU/Linux - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html