From owner-freebsd-chat Sat Nov 23 22:14:53 2002 Delivered-To: freebsd-chat@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B69AD37B401 for ; Sat, 23 Nov 2002 22:14:51 -0800 (PST) Received: from gull.mail.pas.earthlink.net (gull.mail.pas.earthlink.net [207.217.120.84]) by mx1.FreeBSD.org (Postfix) with ESMTP id 50A3543E4A for ; Sat, 23 Nov 2002 22:14:51 -0800 (PST) (envelope-from tlambert2@mindspring.com) Received: from pool0280.cvx21-bradley.dialup.earthlink.net ([209.179.193.25] helo=mindspring.com) by gull.mail.pas.earthlink.net with esmtp (Exim 3.33 #1) id 18Fq2b-0005Yu-00; Sat, 23 Nov 2002 22:14:50 -0800 Message-ID: <3DE06DE9.D3CC595F@mindspring.com> Date: Sat, 23 Nov 2002 22:12:57 -0800 From: Terry Lambert X-Mailer: Mozilla 4.79 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: drew-dated-1038529607.6fb7a6@poured.net Cc: freebsd-chat@freebsd.org Subject: Re: mail queues on softdep (was Re: Sharing calendars?) References: <3DE00781.F47E59A1@mindspring.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Drew Raines wrote: > Terry Lambert writes: > > Drew Raines wrote: > >> Brad Knowles writes: > >> > At the very least, if you do decide to continue with qmail, > >> > make sure you turn off softupdates for that filesystem. > >> > >> By ``that'' filesystem, he means /var/qmail/queue. You can keep > >> everything else on a vanilla FFS partition. It's the same > >> recommendation for any mail queue whose contents you care about. > > > > Why are soft updates bad for mail queues, in your opinions? > > My opinions aren't authoritative because I've never (knowingly) > experienced it, but apparently a message could be lost if it's > accepted by the MTA and there's a system failure before the > metadata gets written to the disk. OK. I understand. The answer is that sendmail will fsync the files, so it's not a probleem, before before giving the "250 Accepted for delivery", since that response means that the data has been committed to stable storage, and your system accepts complete responsibility for its reliable delivery. > This could happen with sync, too, I guess, but the latency is > increased with soft updates. There might be characteristics of > qmail's queue which causes it to be more susceptible than others, > but the logic seems to apply to all. Yes, it would have to be qmail not making the system call needed to commit the data to stable storage, before giving the "250" back to the sending system. Technically, qmail is in violation of the RFC, if indeed this is a problem. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message