From owner-freebsd-hackers Tue Feb 6 10: 2: 2 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from brutus.conectiva.com.br (brutus.conectiva.com.br [200.250.58.146]) by hub.freebsd.org (Postfix) with ESMTP id 1ADE637B401 for ; Tue, 6 Feb 2001 10:01:42 -0800 (PST) Received: from localhost (riel@localhost) by brutus.conectiva.com.br (8.11.2/8.11.2) with ESMTP id f16Hxr425935; Tue, 6 Feb 2001 15:59:53 -0200 X-Authentication-Warning: duckman.distro.conectiva: riel owned process doing -bs Date: Tue, 6 Feb 2001 15:59:53 -0200 (BRDT) From: Rik van Riel X-Sender: riel@duckman.distro.conectiva To: Mike Silbersack Cc: Poul-Henning Kamp , Charles Randall , "'Matt Dillon'" , Dan Phoenix , Alfred Perlstein , Jos Backus , freebsd-hackers@FreeBSD.ORG Subject: Re: soft updates and qmail (RE: qmail IO problems) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, 6 Feb 2001, Mike Silbersack wrote: > On Tue, 6 Feb 2001, Rik van Riel wrote: > > > The system call used to guarantee this is fsync (and friends?); > > if qmail doesn't use it but makes assumptions that aren't true > > on any decent OS out there ... > > Well, the various qmail programs do seem to fsync (though I'm > not sure if it's in the right places.) > ftp://elektroni.ee.tut.fi/pub/qmail_linux_metadata_message : > So what is this all about? qmail relies on the BSD semantics of ^^^ > immediate update of directories on the disk when link(), > unlink(), open() and rename() calls are used. Pre-softupdate BSD semantics, apparently. Doesn't sound like the smartest thing to do when you want a reliable MTA... > But Linux writes them to the disk asynchronously. My library > loaded before libc changes those calls to do the corresponding > directory writes too. Then qmail should be reliable against > power outages also in Linux. If djb could be considered to take things like reliability and the SMTP specification into account, and not just security, then qmail would have the potential to be a pretty decent mailer. As it is, I can only recommend people to go with something like postfix, Exim or zmailer ... regards, Rik -- Linux MM bugzilla: http://linux-mm.org/bugzilla.shtml Virtual memory is like a game you can't win; However, without VM there's truly nothing to lose... http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message