From owner-freebsd-fs@FreeBSD.ORG Sun Jun 9 02:59:44 2013 Return-Path: Delivered-To: fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 4B6EFEBF; Sun, 9 Jun 2013 02:59:44 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-pd0-f173.google.com (mail-pd0-f173.google.com [209.85.192.173]) by mx1.freebsd.org (Postfix) with ESMTP id 262121919; Sun, 9 Jun 2013 02:59:43 +0000 (UTC) Received: by mail-pd0-f173.google.com with SMTP id v14so2328773pde.18 for ; Sat, 08 Jun 2013 19:59:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=bK7ZJ30mOgv+o+SdSrCGZ6glYF6nqX0U4ob2VewHOSw=; b=q85BECHlYON5f9ydymr1f/uF0gziErmNIbGERxcnSLdnYxXX2t/5HRnurZblx8VCE9 rbGJUAntksUi/SemdEQ6WNlRKM+/BGPQhBm1J/0zpvNnSY0GfMRuNU3mUgetm1nkNU7B 34h7v7mI5fiPYWltWBOm13yp5gElRmO/rY2M/S2q/d2oAYobp0cWMQCAXVo7umbXZW1K 34uUBbRKwEtXwpwY8HX3gdNR3xCBmVD4hrC10cKM0CUtYP3VzYRQl087yorCMkJwtaEn RgJ9/iWt3tI+YYugeyd++IknPM3u2xuhpyrsm4VVdDCg0cxHoLxjmrz8O2ts265YcjL2 +/6A== MIME-Version: 1.0 X-Received: by 10.66.175.205 with SMTP id cc13mr8616764pac.191.1370746783517; Sat, 08 Jun 2013 19:59:43 -0700 (PDT) Received: by 10.70.31.195 with HTTP; Sat, 8 Jun 2013 19:59:43 -0700 (PDT) In-Reply-To: <20130608213331.GB18201@icarus.home.lan> References: <16FEF774EE8E4100AD2CAEC65276A49D@multiplay.co.uk> <20130608213331.GB18201@icarus.home.lan> Date: Sat, 8 Jun 2013 21:59:43 -0500 Message-ID: Subject: Re: Changing the default for ZFS atime to off? From: Adam Vande More To: Jeremy Chadwick Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: Steven Hartland , fs@freebsd.org X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 09 Jun 2013 02:59:44 -0000 On Sat, Jun 8, 2013 at 4:33 PM, Jeremy Chadwick wrote: > I **strongly** oppose this change, for one key reason: the classic > Berkeley UNIX mail spool format (known as "mbox"), which is still > predominantly used on most UNIX systems today. > > Mail clients which read mbox files require a combination of atime and > mtime to determine if new mail has arrived within the mailbox. If > mtime > atime, then there's new mail. Not all mail clients support > alternate methods of detection (for example mutt has check_mbox_size, > which has had bugs/problems in the past (Google check_mbox_size), > and is fallible in other ways). > > Further points: > > - FreeBSD comes with sendmail (MTA/MDA), which supports only mbox > natively > - FreeBSD comes with mail/Mail/mailx (client), which only supports > only mbox natively > - FreeBSD comes with biff/comsat, as well as from(1), which supports > only mbox natively > Most modern linuce use relatime eg the benefits of noatime and preserving functionality for mail stuff. https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Power_Management_Guide/Relatime.html -- Adam Vande More